[go: up one dir, main page]

WO2021031648A1 - Evpn和vpls共存双活的方法、设备及系统 - Google Patents

Evpn和vpls共存双活的方法、设备及系统 Download PDF

Info

Publication number
WO2021031648A1
WO2021031648A1 PCT/CN2020/092705 CN2020092705W WO2021031648A1 WO 2021031648 A1 WO2021031648 A1 WO 2021031648A1 CN 2020092705 W CN2020092705 W CN 2020092705W WO 2021031648 A1 WO2021031648 A1 WO 2021031648A1
Authority
WO
WIPO (PCT)
Prior art keywords
network
traffic
cross
mac
homed
Prior art date
Application number
PCT/CN2020/092705
Other languages
English (en)
French (fr)
Inventor
王海波
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to EP20855159.8A priority Critical patent/EP4016932A4/en
Publication of WO2021031648A1 publication Critical patent/WO2021031648A1/zh
Priority to US17/675,218 priority patent/US20220174006A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/60—Router architectures
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/46—Interconnection of networks
    • H04L12/4633—Interconnection of networks using encapsulation techniques, e.g. tunneling
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/46—Interconnection of networks
    • H04L12/4641—Virtual LANs, VLANs, e.g. virtual private networks [VPN]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L41/00—Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
    • H04L41/12—Discovery or management of network topologies
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L41/00—Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
    • H04L41/14—Network analysis or design
    • H04L41/145—Network analysis or design involving simulating, designing, planning or modelling of a network
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/22—Alternate routing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/38—Flow based routing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/42—Centralised routing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/50—Routing or path finding of packets in data switching networks using label swapping, e.g. multi-protocol label switch [MPLS]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/66—Layer 2 routing, e.g. in Ethernet based MAN's
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/68—Pseudowire emulation, e.g. IETF WG PWE3
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/74—Address processing for routing
    • H04L45/745—Address table lookup; Address filtering
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L2101/00—Indexing scheme associated with group H04L61/00
    • H04L2101/60—Types of network addresses
    • H04L2101/618—Details of network addresses
    • H04L2101/622—Layer-2 addresses, e.g. medium access control [MAC] addresses

Definitions

  • the embodiments of this application relate to the field of communication technology, and in particular to a method, device and method for coexisting dual-active Ethernet virtual private network (English: Ethernet Virtual Private Network, EVPN) and virtual private local area network (English: Virtual Private Lan Service, VPLS) system.
  • EVPN Ethernet Virtual Private Network
  • VPLS Virtual Private Lan Service
  • VPLS is a Layer 2 packet bearer technology, essentially a Layer 2 virtual private network (English: Layer 2) based on Internet Protocol/Multiprotocol Label Switching (English: Internet Protocol/Multiprotocol Label Switching, IP/MPLS) and Ethernet technology. Virtual Private Network, L2VPN) technology.
  • the core idea of VPLS technology is to use the signaling protocol to establish and maintain pseudowire PW (English: Pseudo Wire, PW) between Provider Edge (PE) devices in the VPLS instance, and encapsulate the Layer 2 protocol frame in Transmission and exchange are performed on the PW.
  • PW pseudowire PW
  • PE Provider Edge
  • PW is a simulated point-to-point bidirectional connection between a pair of devices established in a packet-switched network (English: Packet-Switched Network, PSN) using Layer 2 technology. Operators use PE and interconnection PW to transmit service data streams between customers' LANs in different areas on PSN, thereby interconnecting multiple LANs of customers in different areas into a simulated LAN, which is called a VPLS instance.
  • the regional LAN can be regarded as a network segment of the simulated LAN.
  • EVPN Extranet Virtual Private Network
  • BGP Border Gateway Protocol
  • MAC Media Access Control
  • CE Customer Edge
  • the CE device multi-homing access to EVPN includes multi-homing access to EVPN through an Ethernet link, that is, a CE device is connected to multiple network side devices through multiple links.
  • the embodiments of the present application provide a message processing method, device, and system, which are used to solve the technical problem of the conventional EVPN and VPLS coexisting active-active network that traffic cannot be forwarded normally.
  • the method By executing the method, the effective connection between the EVPN and the VPLS network can be realized, and the normal operation of the service can be guaranteed.
  • the embodiments of the present application provide a traffic forwarding method in which a first network device and multiple other network devices in the network run EVPN, wherein the first network device acts as a PE device and the EVPN At least one PE in the VPLS forms a multi-homing structure for one CE device or terminal device; connects with at least one PE in the VPLS through a cross-network PW; receives data traffic; according to the matching result of the data traffic with the following conditions, The data traffic is forwarded, wherein the conditions include: (1) being sent by other PE devices via the cross-network PW of the first network device, (2) needing to be forwarded by the first network device to via the cross-network PW The PE device connected to the PW, and/or (3) includes a cross-network PW mark.
  • the mode of the cross-network PW connected to the first network device may be ordinary PW, PW protection group and not supporting dual reception, or PW protection group and supporting dual reception. mode.
  • the traffic may be multicast BUM traffic or unicast traffic.
  • one of the cross-network PWs can be used as the designated forwarding DF PW, and the remaining cross-network PWs can be used as backup designated forwarding BDF PWs.
  • the multi-homing structure PE on the EVPN side forwards traffic to the PE device on the VPLS side.
  • the data flow when the data flow matches the corresponding conditions, the data flow can be forwarded according to the following forwarding rules.
  • the first network device forwards the BUM traffic based on the following rules: the traffic entering through the AC port can be copied to the cross-network DF PW; by the AC port Incoming traffic is not replicated to the cross-network BDF PW; traffic entered by the ordinary EVPN peer EVPN Peer is not replicated to the cross-network PW; traffic from the multi-homed PE is replicated to the cross-network DF PW; traffic received by the cross-network PW Only copy to the AC port; wherein, the ordinary EVPN Peer and at least one of the multiple PE devices constitute an EVPN Peer, but it does not belong to a multi-homed PE.
  • the first network device determines the forwarding path based on MAC address learning, and the MAC address learning rules are as follows: the multi-homed PE learns MAC from the DF PW; The owned PE does not learn the MAC from the BDF PW; after the multi-homed PE learns the MAC from the DF PW, it synchronizes to the EVPN Peer and adds the cross-network PW tag; after the EVPN Peer discovers the MAC with the cross-network PW tag, if it finds a local report that carries the MAC The ESI tag value in the text points its MAC to the address of the PE device that sent the message, otherwise the MAC is discarded.
  • the first network device forwards the BUM traffic based on the following rules: the traffic entering through the AC port can be forwarded to the cross-network DF PW Replication; the traffic from the ordinary EVPN Peer is not replicated to the cross-network PW; the traffic from the multi-homed PE is replicated to the cross-network DF PW; the traffic received by the cross-network PW is replicated to the AC port and the multi-homed PE, and to the multi-homed PE
  • the ESI tag is carried during replication; after the multi-homed PE receives the traffic carrying the ESI tag, it only replicates to the AC port; where the ordinary EVPN Peer and at least one of the multiple PE devices constitute an EVPN Peer, but it does not itself Belongs to multiple home PE.
  • the cross-network PW mode is the PW protection group and does not support dual-receiving
  • the forwarded traffic is BUM traffic
  • the following forwarding rule can also be included: the traffic entering through the AC port does not go to the cross-network BDF PW copy.
  • the overhead of forwarding traffic can be saved, and traffic forwarding bandwidth can be saved.
  • the first network device determines the forwarding path based on MAC address learning, and the MAC address learning rules are as follows: DF PW learns MAC; multi-homed PE does not learn MAC from BDF PW; multi-homed PE learns MAC from DF PW, then synchronizes to EVPN Peer, adding cross-network PW flag; EVPN Peer discovers cross-network PW-marked MAC, if local If it has the ESI tag value in the message carrying the MAC, it will point its MAC to the address of the PE device that sent the message, otherwise the MAC will be discarded.
  • the first network device forwards the BUM traffic based on the following rules: the traffic entering through the AC port can be copied to the cross-network DF PW ; The traffic entering from the AC port can be copied to the cross-network BDF PW; the traffic entering from the ordinary EVPN Peer is not copied to the cross-network PW; the traffic entering from the multi-homed PE is not copied to the cross-network DF PW; the cross-network PW received The traffic is copied to the AC port and the multi-homed PE, and the ESI tag is carried when it is copied to the multi-homed PE; after the multi-homed PE receives the traffic carrying the ESI label, it only replicates to the AC port; where the common EVPN Peer and the multiple At least one of the PE devices constitutes an EVPN Peer, but it does not belong to a multi-homed PE.
  • the first network device determines the forwarding path based on MAC address learning, and the MAC address learning rules are as follows: multi-homing PE from DF PW learns MAC; multi-homed PE learns MAC from BDF PW; multi-homed PE learns MAC from DF PW, then synchronizes to EVPN Peer, and adds cross-network PW mark; after EVPN Peer finds MAC with cross-network PW mark, if it finds that it has a local carry The ESI tag value in the MAC message will point its MAC to the address of the PE device that sent the message, otherwise the MAC will be discarded.
  • the EVPN and VPLS coexisting active-active network can be effectively connected to the EVPN side and VPLS, avoiding the formation of VPLS devices when receiving traffic Jump to ensure the normal operation of the business.
  • the first network device learns MAC when forwarding unicast traffic
  • the address rule further includes: After the EVPN Peer discovers the MAC marked by the cross-network PW, if it finds that the local ESI value in the packet carrying the MAC is found, then the BDF PW corresponding to the ESI value is set as the backup path. When the primary path for forwarding unicast traffic is unavailable, the backup path can be used to complete the forwarding of unicast traffic, thereby improving the robustness and security of network communication.
  • the way to add a cross-network PW flag to a MAC address is to add a new MAC extended community attribute, mark and distinguish the specific type of cross-network PW through the field Flags; or reuse existing MAC migration attributes, Use the free bits of the field Flags to mark and distinguish the specific type of PW.
  • an embodiment of the present application provides a network device, the network device includes: a memory, configured to store computer-readable instructions; and a processor, configured to call the computer-readable instructions to execute: The network equipment and multiple other network equipment run EVPN, where the network equipment as the operator edge PE equipment and at least one PE in the EVPN form a multi-homing structure for one CE equipment or terminal equipment; and at least one in the VPLS A PE is connected through a cross-network PW; receives data traffic; forwards the data traffic according to the matching result of the data traffic with the following conditions, where the conditions include: (1) other PE equipment via the The cross-network PW transmission of the network device, (2) needs to be forwarded by the network device to the PE device connected via the cross-network PW, and/or (3) includes the mark of the cross-network PW.
  • the mode of the cross-network PW connecting the network device may be a normal PW, a PW protection group and not supporting dual reception, or a PW protection group and supporting dual reception mode.
  • the traffic may be multicast BUM traffic or unicast traffic.
  • one of the cross-network PWs can be used as the designated forwarding DF PW, and the remaining cross-network PWs can be used as backup designated forwarding BDF PWs.
  • the multi-homing structure PE on the EVPN side forwards traffic to the PE device on the VPLS side.
  • the data flow when the data flow matches the corresponding conditions, the data flow can be forwarded according to the following forwarding rules.
  • the network device forwards the BUM traffic based on the following rules: the traffic entered through the AC port can be copied to the cross-network DF PW; the traffic entered by the AC port The traffic is not replicated to the cross-network BDF PW; the traffic entered by the ordinary EVPN peer EVPN Peer is not replicated to the cross-network PW; the traffic from the multi-homed PE is replicated to the cross-network DF PW; the traffic received by the cross-network PW is only AC port replication; wherein, the ordinary EVPN Peer and at least one of the multiple PE devices constitute an EVPN Peer, but it does not belong to a multi-homed PE.
  • the network device determines the forwarding path based on MAC address learning, and the MAC address learning rules are as follows: multi-homing PE learns MAC from DF PW; multi-homing PE Do not learn MAC from BDF PW; after multi-homed PE learns MAC from DF PW, it synchronizes to EVPN Peer and adds cross-network PW flag; after EVPN Peer discovers the MAC with cross-network PW flag, if it finds that there is a local packet carrying the MAC If the ESI tag value is set to the value of the ESI tag, point its MAC to the address of the PE device that sent the message, otherwise discard the MAC.
  • the network device forwards the BUM traffic based on the following rules: the traffic entering through the AC port can be copied to the cross-network DF PW; The traffic entered by the ordinary EVPN Peer is not replicated to the cross-network PW; the traffic from the multi-homed PE is replicated to the cross-network DF PW; the traffic received by the cross-network PW is replicated to the AC port and the multi-homed PE, and when it is replicated to the multi-homed PE Carrying ESI tags; after multi-homed PE receives the traffic carrying ESI tags, it only replicates to the AC port; wherein, the ordinary EVPN Peer and at least one of the multiple PE devices constitute an EVPN Peer, but it does not belong to the multi-homed PE itself. Owned by PE.
  • the cross-network PW mode is the PW protection group and does not support dual-receiving
  • the forwarded traffic is BUM traffic
  • the following forwarding rule can also be included: the traffic entering through the AC port does not go to the cross-network BDF PW copy.
  • the overhead of forwarding traffic can be saved, and traffic forwarding bandwidth can be saved.
  • the network device determines the forwarding path based on MAC address learning.
  • the MAC address learning rules are as follows: Multi-homing PE from DF PW Learn MAC; multi-homed PE does not learn MAC from BDF PW; multi-homed PE learns MAC from DF PW, synchronizes to EVPN Peer, and adds cross-network PW flag; after EVPN Peer discovers cross-network PW-marked MAC, if it finds that it has a local carry
  • the ESI tag value in the MAC message will point its MAC to the address of the PE device that sent the message, otherwise the MAC will be discarded.
  • the network device forwards the BUM traffic based on the following rules: the traffic entering through the AC port can be copied to the cross-network DF PW; The traffic that enters the AC port can be replicated to the cross-network BDF PW; the traffic that enters from the ordinary EVPN Peer is not replicated to the cross-network PW; the traffic from the multi-homed PE is not replicated to the cross-network DF PW; the traffic received by the cross-network PW is redirected The AC port and the multi-homed PE are replicated, and the ESI tag is carried when replicating to the multi-homed PE; the multi-homed PE only replicates to the AC port after receiving the traffic carrying the ESI tag; wherein, the ordinary EVPN Peer and the multiple PE devices At least one of them constitutes an EVPN Peer, but it does not belong to a multi-
  • the first network device determines the forwarding path based on MAC address learning, and the MAC address learning rules are as follows: multi-homing PE from DF PW learns MAC; multi-homed PE learns MAC from BDF PW; multi-homed PE learns MAC from DF PW, then synchronizes to EVPN Peer, and adds cross-network PW mark; after EVPN Peer finds MAC with cross-network PW mark, if it finds that it has a local carry The ESI tag value in the MAC message will point its MAC to the address of the PE device that sent the message, otherwise the MAC will be discarded.
  • the EVPN and VPLS coexisting active-active network can be effectively connected to the EVPN side and VPLS, avoiding the formation of VPLS devices when receiving traffic Jump to ensure the normal operation of the business.
  • the network device learns the MAC address when forwarding unicast traffic
  • the rule further includes: After the EVPN Peer discovers the MAC marked by the cross-network PW, if it finds that the local ESI value in the packet carrying the MAC is found, then the BDF PW corresponding to the ESI value is set as the backup path. When the primary path for forwarding unicast traffic is unavailable, the backup path can be used to complete the forwarding of unicast traffic, thereby improving the robustness and security of network communication.
  • the way to add a cross-network PW flag to a MAC address is to add a new MAC extended community attribute, mark and distinguish the specific type of cross-network PW through the field Flags; or reuse existing MAC migration attributes, Use the free bits of the field Flags to mark and distinguish the specific type of PW.
  • the embodiments of the present application provide a traffic forwarding system, the system includes a plurality of first operator edge PE devices, the plurality of first PE devices are EVPN devices, and the plurality of first PE devices
  • the device forms a multi-homing structure for a customer edge CE device or terminal device; each first PE device in the multi-homing structure is connected to the same at least one second PE device through a cross-network pseudowire PW, and The second PE device is a VPLS device; the first PE device receives data traffic; the first PE device forwards the data traffic according to the result of matching the data traffic with the following conditions, where the conditions include : (1) It is sent by other PE devices via the cross-network PW of the network device, (2) needs to be forwarded by the network device to the PE device connected via the cross-network PW, and/or (3) includes the cross-network PW mark.
  • the mode of the cross-network PW connected to the first PE device may be ordinary PW, PW protection group and not supporting dual reception, or PW protection group and supporting dual reception. mode.
  • the traffic may be multicast BUM traffic or unicast traffic.
  • one of the cross-network PWs can be used as the designated forwarding DF PW, and the remaining cross-network PWs can be used as backup designated forwarding BDF PWs.
  • the multi-homing structure PE on the EVPN side forwards traffic to the PE device on the VPLS side.
  • the data flow when the data flow matches the corresponding conditions, the data flow can be forwarded according to the following forwarding rules.
  • the first PE device forwards the BUM traffic based on the following rules: the traffic entering through the AC port can be copied to the cross-network DF PW; by the AC port Incoming traffic is not replicated to the cross-network BDF PW; traffic entered by the ordinary EVPN peer EVPN Peer is not replicated to the cross-network PW; traffic from the multi-homed PE is replicated to the cross-network DF PW; traffic received by the cross-network PW Only copy to the AC port; wherein, the ordinary EVPN Peer and at least one of the multiple PE devices constitute an EVPN Peer, but it does not belong to a multi-homed PE.
  • the first PE device determines the forwarding path based on MAC address learning, and the MAC address learning rules are as follows: the multi-homing PE learns MAC from DF PW; The owned PE does not learn the MAC from the BDF PW; after the multi-homed PE learns the MAC from the DF PW, it synchronizes to the EVPN Peer and adds the cross-network PW tag; after the EVPN Peer discovers the MAC with the cross-network PW tag, if it finds a local report that carries the MAC The ESI tag value in the text points its MAC to the address of the PE device that sent the message, otherwise the MAC is discarded.
  • the first PE device forwards the BUM traffic based on the following rules: the traffic entering through the AC port can be sent to the cross-network DF PW Replication; the traffic from the ordinary EVPN Peer is not replicated to the cross-network PW; the traffic from the multi-homed PE is replicated to the cross-network DF PW; the traffic received by the cross-network PW is replicated to the AC port and the multi-homed PE, and to the multi-homed PE
  • the ESI tag is carried during replication; after the multi-homed PE receives the traffic carrying the ESI tag, it only replicates to the AC port; where the ordinary EVPN Peer and at least one of the multiple PE devices constitute an EVPN Peer, but it does not itself Belongs to multiple home PE.
  • the cross-network PW mode is the PW protection group and does not support dual-receiving
  • the forwarded traffic is BUM traffic
  • the following forwarding rule can also be included: the traffic entering through the AC port does not go to the cross-network BDF PW copy.
  • the overhead of forwarding traffic can be saved, and traffic forwarding bandwidth can be saved.
  • the first PE device determines the forwarding path based on MAC address learning, and the MAC address learning rules are as follows: DF PW learns MAC; multi-homed PE does not learn MAC from BDF PW; multi-homed PE learns MAC from DF PW, synchronizes to EVPN Peer, and adds cross-network PW mark; EVPN Peer finds MAC with cross-network PW mark, if local If it has the ESI tag value in the message carrying the MAC, it will point its MAC to the address of the PE device that sent the message, otherwise the MAC will be discarded.
  • the first PE device forwards the BUM traffic based on the following rules: the traffic entering through the AC port can be copied to the cross-network DF PW ; The traffic entering from the AC port can be copied to the cross-network BDF PW; the traffic entering from the ordinary EVPN Peer is not copied to the cross-network PW; the traffic entering from the multi-homed PE is not copied to the cross-network DF PW; the cross-network PW received The traffic is copied to the AC port and the multi-homed PE, and the ESI tag is carried when it is copied to the multi-homed PE; after the multi-homed PE receives the traffic carrying the ESI label, it only replicates to the AC port; where the common EVPN Peer and the multiple At least one of the PE devices constitutes an EVPN Peer, but it does not belong to a multi-homed PE.
  • the first PE device determines the forwarding path based on MAC address learning, and the MAC address learning rules are as follows: multi-homing PE from DF PW learns MAC; multi-homed PE learns MAC from BDF PW; multi-homed PE learns MAC from DF PW, then synchronizes to EVPN Peer, and adds cross-network PW mark; after EVPN Peer finds MAC with cross-network PW mark, if it finds that it has a local carry The ESI tag value in the MAC message will point its MAC to the address of the PE device that sent the message, otherwise the MAC will be discarded.
  • the EVPN and VPLS coexisting active-active network can be effectively connected to the EVPN side and VPLS, avoiding the formation of VPLS devices when receiving traffic Jump to ensure the normal operation of the business.
  • the first network device learns MAC when forwarding unicast traffic
  • the address rule further includes: After the EVPN Peer discovers the MAC marked by the cross-network PW, if it finds that the local ESI value in the packet carrying the MAC is found, then the BDF PW corresponding to the ESI value is set as the backup path. When the primary path for forwarding unicast traffic is unavailable, the backup path can be used to complete the forwarding of unicast traffic, thereby improving the robustness and security of network communication.
  • the way to add a cross-network PW flag to a MAC address is to add a new MAC extended community attribute, mark and distinguish the specific type of cross-network PW through the field Flags; or reuse existing MAC migration attributes, Use the free bits of the field Flags to mark and distinguish the specific type of PW.
  • an embodiment of the present application provides a traffic forwarding system, the system includes: a first connection unit, configured to operate an Ethernet virtual private network EVPN between a first network device and multiple other network devices in the network, wherein The first network device as an operator edge PE device and at least one PE in the EVPN form a multi-homing structure for a customer edge CE device or terminal device; the second connection unit is used for the first network device and the virtual At least one PE in the private local area network VPLS is connected by a cross-network pseudowire PW; a receiving unit, for the first network device to receive data traffic; a matching unit, for the first network device according to the matching result of the data traffic and the following conditions , The data traffic is forwarded, wherein the conditions include: (1) sent by other PE devices via the cross-network PW of the first network device, (2) need to be forwarded by the first network device to via The PE equipment connected across the network PW, and/or (3) includes the mark of the cross network PW.
  • the mode of the cross-network PW connected to the first network device may be ordinary PW, PW protection group and not supporting dual reception, or PW protection group and supporting dual reception. mode.
  • the traffic may be multicast BUM traffic or unicast traffic.
  • one of the cross-network PWs can be used as the designated forwarding DF PW, and the remaining cross-network PWs can be used as backup designated forwarding BDF PWs.
  • the multi-homing structure PE on the EVPN side forwards traffic to the PE device on the VPLS side.
  • the data flow when the data flow matches the corresponding conditions, the data flow can be forwarded according to the following forwarding rules.
  • the first network device forwards the BUM traffic based on the following rules: the traffic entering through the AC port can be copied to the cross-network DF PW; by the AC port Incoming traffic is not replicated to the cross-network BDF PW; traffic entered by the ordinary EVPN peer EVPN Peer is not replicated to the cross-network PW; traffic from the multi-homed PE is replicated to the cross-network DF PW; traffic received by the cross-network PW Only copy to the AC port; wherein, the ordinary EVPN Peer and at least one of the multiple PE devices constitute an EVPN Peer, but it does not belong to a multi-homed PE.
  • the first network device determines the forwarding path based on MAC address learning, and the MAC address learning rules are as follows: the multi-homed PE learns MAC from the DF PW; The owned PE does not learn the MAC from the BDF PW; after the multi-homed PE learns the MAC from the DF PW, it synchronizes to the EVPN Peer and adds the cross-network PW tag; after the EVPN Peer discovers the MAC with the cross-network PW tag, if it finds a local report that carries the MAC The ESI tag value in the text points its MAC to the address of the PE device that sent the message, otherwise the MAC is discarded.
  • the first network device forwards the BUM traffic based on the following rules: the traffic entering through the AC port can be forwarded to the cross-network DF PW Replication; the traffic from the ordinary EVPN Peer is not replicated to the cross-network PW; the traffic from the multi-homed PE is replicated to the cross-network DF PW; the traffic received by the cross-network PW is replicated to the AC port and the multi-homed PE, and to the multi-homed PE
  • the ESI tag is carried during replication; after the multi-homed PE receives the traffic carrying the ESI tag, it only replicates to the AC port; where the ordinary EVPN Peer and at least one of the multiple PE devices constitute an EVPN Peer, but it does not itself Belongs to multiple home PE.
  • the cross-network PW mode is the PW protection group and does not support dual-receiving
  • the forwarded traffic is BUM traffic
  • the following forwarding rule can also be included: the traffic entering through the AC port does not go to the cross-network BDF PW copy.
  • the overhead of forwarding traffic can be saved, and traffic forwarding bandwidth can be saved.
  • the first network device determines the forwarding path based on MAC address learning, and the MAC address learning rules are as follows: DF PW learns MAC; multi-homed PE does not learn MAC from BDF PW; multi-homed PE learns MAC from DF PW, synchronizes to EVPN Peer, and adds cross-network PW mark; EVPN Peer finds MAC with cross-network PW mark, if local If it has the ESI tag value in the message carrying the MAC, it will point its MAC to the address of the PE device that sent the message, otherwise the MAC will be discarded.
  • the first network device forwards the BUM traffic based on the following rules: the traffic entering through the AC port can be copied to the cross-network DF PW ; The traffic entering from the AC port can be copied to the cross-network BDF PW; the traffic entering from the ordinary EVPN Peer is not copied to the cross-network PW; the traffic entering from the multi-homed PE is not copied to the cross-network DF PW; the cross-network PW received The traffic is copied to the AC port and the multi-homed PE, and the ESI tag is carried when it is copied to the multi-homed PE; after the multi-homed PE receives the traffic carrying the ESI label, it only replicates to the AC port; where the common EVPN Peer and the multiple At least one of the PE devices constitutes an EVPN Peer, but it does not belong to a multi-homed PE.
  • the first network device determines the forwarding path based on MAC address learning, and the MAC address learning rules are as follows: multi-homing PE from DF PW learns MAC; multi-homed PE learns MAC from BDF PW; multi-homed PE learns MAC from DF PW, then synchronizes to EVPN Peer, and adds cross-network PW mark; after EVPN Peer finds MAC with cross-network PW mark, if it finds that it has a local carry The ESI tag value in the MAC message will point its MAC to the address of the PE device that sent the message, otherwise the MAC will be discarded.
  • the EVPN and VPLS coexisting active-active network can be effectively connected to the EVPN side and VPLS, avoiding the formation of VPLS devices when receiving traffic Jump to ensure the normal operation of the business.
  • the first network device learns MAC when forwarding unicast traffic
  • the address rule further includes: After the EVPN Peer discovers the MAC marked by the cross-network PW, if it finds that the local ESI value in the packet carrying the MAC is found, then the BDF PW corresponding to the ESI value is set as the backup path. When the primary path for forwarding unicast traffic is unavailable, the backup path can be used to complete the forwarding of unicast traffic, thereby improving the robustness and security of network communication.
  • the way to add a cross-network PW flag to a MAC address is to add a new MAC extended community attribute, mark and distinguish the specific type of cross-network PW through the field Flags; or reuse existing MAC migration attributes, Use the free bits of the field Flags to mark and distinguish the specific type of PW.
  • the embodiments of the present application provide a computer-readable storage medium or computer program product for storing a computer program, and the computer program is used to execute any possible design method in the first aspect.
  • Figure 1 is a schematic diagram of a VPLS network structure provided in the prior art
  • Figure 2 is a schematic diagram of an EVPN network structure provided by an embodiment of the present invention.
  • FIG. 3 is a schematic diagram of an application network scenario of a traffic forwarding method provided by an embodiment of the application
  • FIG. 4 is a schematic flowchart of a traffic forwarding method provided by an embodiment of this application.
  • 5a-5d are schematic diagrams of the forwarding process of BUM traffic provided by an embodiment of this application.
  • FIG. 6 is a schematic diagram of a forwarding process of unicast traffic according to an embodiment of this application.
  • FIG. 7 is a schematic diagram of another BUM traffic forwarding process provided by an embodiment of this application.
  • FIG. 8 is a schematic diagram of another BUM traffic forwarding process provided by an embodiment of this application.
  • 9a-9b are schematic diagrams of the MAC address field format provided by an embodiment of the application.
  • FIG. 10 is a schematic structural diagram of a network device provided by an embodiment of this application.
  • FIG. 11 is a schematic structural diagram of a traffic forwarding system provided by an embodiment of this application.
  • Figure 1 shows the topology model of the VPLS network structure in the interactive network television (English: Internet Protocol Television, IPTV) business scenario.
  • Optical cable terminal equipment Optical Line Terminal, OLT
  • CE Customer Edge
  • the OLT is connected to the corresponding operator edge PE equipment through the attachment circuit (AC), and each PE equipment is connected by a fully meshed pseudowire (English: Full-mesh PW), that is, each PE equipment passes through PWs are connected in pairs.
  • This networking model is also applicable to services other than IPTV.
  • FIG. 2 shows a schematic structural diagram of an exemplary EVPN network.
  • the network 100 includes a backbone network provided by a service provider and multiple EVPN sites (English: Site).
  • the backbone network includes PE devices PE1, PE2, and PE3 and multiple backbone (English: Provider, P) devices (not shown in the figure).
  • the multiple EVPN sites include a first site and a second site, where the first site and the second site belong to the same EVPN1.
  • CE4 is dual-homed to PE1 and PE2, while CE5 is single-homed to PE3.
  • the Ethernet segment route is sent to each other, according to the Ethernet segment identifier (English: Ethernet Segment Identifier, ESI) value carried in the Ethernet segment route.
  • ESI Ethernet Segment Identifier
  • known unicast traffic can usually be forwarded, and multicast (English: BUM) traffic can also be forwarded.
  • the known unicast traffic may also be referred to as unicast traffic for short.
  • the BUM traffic generally includes broadcast traffic, multicast traffic, and unicast traffic with unknown destination addresses.
  • EVPN introduces Designated Forwarder (English: Designated Forwarder, DF) election mechanism is adopted, that is, a PE is designated from PE1 and PE2 to forward BUM traffic.
  • PE1 and PE2 can determine the master and backup devices through cross-device link aggregation (English: Multi-Chassis Link Aggregation Group, MC-LAG).
  • PE1 is elected as the DF of CE4 and can also be called the master device, while PE2 is the backup DF (English: Backup DF, BDF), and can also be called the slave device.
  • the BUM traffic sent from the direction of CE5 is only forwarded from PE1 to CE4, and PE2 as the BDF does not forward the BUM traffic when PE1 is working normally.
  • the Ethernet link can be active or inactive.
  • the active state means that the Ethernet link can be used to forward data streams.
  • the single-active mode means that only one Ethernet link is active, and the other one or more Ethernet links are inactive.
  • the multi-active mode means that the status of part of the Ethernet links in the Ethernet link segment is active, and the status of the other part of the Ethernet links is inactive.
  • the active mode of PE1 and PE2, which are connected to CE4 at the same time is configured to be active-active mode, that is, CE4 supports dual-homed active-active at this time.
  • CE4 supports dual-homed active-active at this time.
  • EVPN also supports Aliasing (English: Aliasing) function.
  • the master device PE can learn the MAC address on the CE side, while the slave device PE may not learn the MAC address on the CE side for some reasons.
  • the remote PE can be dual-homing
  • the ESI value carried by the Ethernet automatic discovery route (English: Ethernet AD Route) sent by the PE can be used to perceive the MAC address reachability on the CE side.
  • This function is called an alias.
  • only PE1 of PE1 and PE2 sends a MAC/IP address advertisement route (English: MAC/IP Advertisement Route) carrying the MAC address of the CE4 side to PE3, but PE3 can use the ESI value carried by Ethernet AD Route , Namely ESI1, can perceive that PE2, which is also marked with the value of ESI1, can also reach CE4, which can form load sharing.
  • EVPN defines the split horizon function, that is, when PE1 receives BUM traffic from CE4, it will be forwarded to PE2, and PE2 will check the EVPN ESI carried in the traffic after receiving the packet.
  • Label (English: EVPN ESI Label), if the ESI value in the label is found to be equal to the ESI value of the network segment connecting PE2 and CE4, PE2 will not send the BUM traffic to CE4, thereby avoiding loops.
  • CE can also be attributed to more than two PE devices. At this time, all PE devices belonging to the same CE device are assigned the same ESI value.
  • multi-homing PE devices can be set to multi-active mode, thereby forming load sharing between each other. The above method is called CE multiple home and multiple live.
  • other device types may also be multi-homed to multiple PE devices, and the other device types may be terminal devices, for example.
  • the multi-homing includes a dual-homing situation, and a multi-active mode or a single-active mode is set for multiple PE devices as required, which can be set in combination with specific application scenarios. In either case, when the multi-homing and multi-live are at most two PE devices, the implementation mechanism is still similar to the dual-homing and dual-active mode.
  • the operator's network will involve the conversion from the VPLS network to the EVPN network.
  • operators may only want to modify some PE equipment. Taking the IPTV service type shown in Figure 1 as an example, you may only want to transform the PE device side connected to the OLT device, that is, the left PE device to support EVPN, but you do not want to modify the configuration of the IPTV side, that is, the right PE device. At this point, if you simply reserve the left PE device to use the VPLS PW mechanism to transmit data, or modify it to use the EVPN mechanism to transmit data, problems may occur.
  • the BUM traffic of the right PE device passes through the two left PE devices, which will form redundancy on the OLT device; and if the left PE device uses the EVPN mechanism, then The BUM traffic sent by the OLT to the IPTV side will continuously hop on the right PE, causing various possible network problems.
  • the technical solutions described in the embodiments of the present application can be applied to a network where EVPN and VPLS coexist in a dual-active network.
  • Figure 3 shows a possible scenario where EVPN and VPLS coexist in a dual-active network.
  • the operator's edge equipment PE21, PE22, and PE25 support EVPN after network transformation, while the operator's edge equipment PE23 and PE24 are still traditional VPLS.
  • PE23 and PE24 need to establish a VPLS PW connection
  • PE23 and PE24 need to establish a VPLS PW connection with the modified PE21, PE22, and PE25 respectively.
  • CE1 is dual-homed to PE21 and PE22, and PE21 and PE22 are configured as dual-active.
  • PE25 is transformed to support EVPN, it does not support CE dual-homing like PE21 and PE22.
  • Hyperactive but as a general PE device supporting EVPN to provide access to CE15.
  • PE21, PE22, and PE25 form an EVPN peer (English: EVPN Peer). It should be noted that those skilled in the art should understand that the scenario shown in FIG. 3 and the specific implementation manner of the embodiments described based on the scenario thereafter are merely examples, and should not constitute a limitation to the present application.
  • the embodiment of this application first defines a cross-network PW mode.
  • the PW of this mode is suitable for the PW connection between the multi-homed PE device on the EVPN side and the PE device on the VPLS side, and needs to meet certain EVPN side and VPLS.
  • the replication and forwarding rules between the two sides ensure the normal forwarding of traffic between the EVPN side and the VPLS side.
  • the copy and forwarding rules between the EVPN side and the VPLS side refer to the rules followed when the PE devices on the EVPN side and the VPLS side communicate with each other, and when only the PEs on the EVPN side communicate with each other, or only the PE on the VPLS side
  • the general rules of EVPN or VPLS are respectively followed, and the above explanation is applicable to multiple or all embodiments of this application.
  • the embodiment of the present application provides a traffic forwarding method 400.
  • the flow of the method 400 is shown in FIG. 4, and specifically includes the following content.
  • the first network device and multiple other network devices in the network run Ethernet virtual private network EVPN, where the first network device as an operator edge PE device and at least one PE in the EVPN form a customer edge CE Multi-homing structure of equipment or terminal equipment;
  • S410 is connected to at least one PE in the virtual private local area network VPLS through a cross-network pseudowire PW;
  • the first network device receives data traffic.
  • S420 The first network device forwards the data flow according to the matching result of the data flow with the following conditions, where the conditions include:
  • PE21 as the first network device complies with the network structure described in S405 and S410.
  • the PE21 receives the BUM traffic sent by the PE22 device.
  • the PE21 determines whether the BUM traffic meets one or more of the three conditions in S410.
  • S420 PE21 determines that the BUM traffic needs to be forwarded to PE23 via the cross-network PW of ESI1 DF PW, so that PE23 can forward the BUM traffic to CE12, which meets the condition (2) in S420.
  • the EVPN side can include one or more groups of multi-homed PEs, and each PE device in each group of multi-homed PEs passes through the same PE device on the VPLS side
  • the PWs are connected, and the PWs connected to each group of multi-homed PEs are in a cross-network PW mode.
  • the PW type used to connect the EVPN side and the VPLS side is a normal mode PW, such as a full mesh connection Full -mesh networking mode.
  • PE23 actually establishes PW connections with PE21 and PE22 at the same time, that is, for PE21 and PE22, the PWs respectively to PE23 actually constitute a group of dual-homing PWs.
  • both PE21 and PE22 can handle it.
  • the PWs between PE21 and PE23, and between PE22 and PE23 are all set to cross-network mode PWs, and the same ESI value is set to ESI1 for these two PWs to identify that they are dual-homing.
  • the PWs between PE21 and PE24, and between PE22 and PE24 are also set to cross-network mode PWs, and the same ESI value is set to ESI2 for these two PWs.
  • the network Based on whether the traffic type is unicast traffic or BUM traffic, the network includes at least two possible scenarios, and the corresponding traffic processing methods are as follows.
  • the PW is a normal mode PW, and the forwarded traffic is BUM traffic.
  • the BUM traffic replication rule in a single EVPN network is described here first, which is referred to as the general rule of EVPN in the embodiment of the present invention.
  • the PE device receives the BUM traffic sent by a CE device, it copies the BUM to all locally connected access circuits AC and the EVPN peer (English: Peer) that exchanges messages with it. flow.
  • the AC is a link through which the CE device or other user equipment accesses the PE, and the copied traffic can be sent to the CE device or other user equipment through the AC.
  • the BUM traffic is copied to all locally connected ACs, and no longer to its EVPN Peer.
  • the other PE device when the other PE device replicates the BUM traffic to the AC, it performs split horizon processing according to the ESI Label carried in the BUM traffic, that is, when the other PE device discovers the ESI carried in the BUM traffic
  • the label is the same as the ESI value stored locally, and is set as the BDF role corresponding to the ESI value
  • the BUM traffic is no longer copied to the corresponding AC.
  • PE21 receives the BUM traffic sent by CE11 via AC, it copies to the AC port used to access CE14 and PE22 and PE25 as its EVPN Peer. The BUM traffic.
  • PE22 After PE22 receives the BUM traffic sent by PE21, it copies the BUM traffic to the AC port used to access CE16. Since PE22 finds that the ESI Label in the message received from PE21 is the same as the ESI value stored locally, it no longer copies the BUM traffic to the AC port corresponding to CE11 that is set to ESI BDF.
  • the BUM traffic replication rule in a single VPLS network is described.
  • the embodiment of the present invention is referred to as the general rule of VPLS ordinary PW.
  • the PE device forwards the traffic received from the CE device to all PWs, but does not forward the traffic received from any PE device to avoid loops.
  • the ordinary EVPN Peer described in the embodiment of the present invention refers to a PE device that is a device of the EVPN type itself, but is not a member of any multi-homed PE group in the network.
  • the PE25 shown in FIG. 3 is an ordinary EVPN Peer. More specifically, the PE25 as an ordinary EVPN Peer is also directly connected to the PE device on the VPLS side through a PW.
  • PE21 and PE22 are respectively connected to PE23 through a dual-homing PW across the network.
  • the PW connecting PE21 and PE23, and PE22 and PE23 are marked with the same ESI value, that is, ESI1.
  • the cross-network PW connecting the PE21 and PE23 is marked as ESI1 DF PW
  • the cross-network PW connecting PE22 and PE23 is marked as ESI1 BDF PW.
  • the specific marking method can be realized by setting a newly added PW field, for example.
  • the cross-network PW connecting PE22 and PE24 is marked as ESI2 DF PW
  • the cross-network PW connecting PE21 and PE24 is marked as ESI2 BDF PW.
  • the replication and forwarding rules between the EVPN side and the VPLS side are specifically as follows:
  • the traffic that R505 enters through the AC port can be copied to the cross-network DF PW;
  • the traffic received by the R525 cross-network PW is only copied to the AC port.
  • Figure 5a shows the replication and forwarding process when the BUM1 traffic sent from the CE11 on the EVPN side is first received by the PE21.
  • PE21 On the EVPN side, after the BUM1 traffic sent by CE11 is received by PE21, PE21 will copy the BUM1 traffic to the AC port of PE21 for access to CE14 in accordance with EVPN's general rules for BUM1 traffic replication and forwarding, but will not send it to PE21.
  • the AC port corresponding to CE11 of the BUM1 traffic source is copied, and PE21 will also copy the BUM1 traffic to all its EVPN Peers, namely PE22 and PE25.
  • the BUM1 traffic When the BUM1 traffic is forwarded by PE21 to PE23 or PE24, the BUM1 traffic will be sent from the EVPN side to the VPLS side.
  • the above-mentioned replication rules R505 and R510 need to be applied, that is, PE21 replicates BUM1 traffic to the cross-network PW marked DF PW to send to the PE23, and PE21 finds that the cross-network PW between it and PE24 is marked as BDF PW, so it does not copy BUM1 traffic to the cross-network PW marked as BDF PW, so PE24 will not receive CE11 sent by PE21 BUM1 traffic.
  • PE22 After PE22 receives the BUM1 traffic copied by PE21, based on the general rules of EVPN, it sends the BUM1 traffic to the AC port on PE22 for access to CE16 in the EVPN side. In addition, PE22 finds that the ESI Label carried in the BUM1 traffic is the same as the ESI value stored locally, that is, the BUM1 traffic comes from PE21 that has a CE11 dual-homing relationship with it, and PE22 is marked as BDF in the CE11 dual-homing device. At this time, PE22 no longer forwards BUM1 traffic to CE11 based on the EVPN split horizon principle.
  • the PE22 will no longer copy BUM1 traffic to other EVPN Peers, thereby avoiding loops.
  • PE22 forwards BUM1 traffic to PE23 or PE24
  • PE22 finds that BUM1 traffic is dual-homed to PE21, and needs to apply the R520 replication rule. Therefore, PE22 replicates BUM1 traffic to the cross-network PW marked as DF PW, and then forwards it. To PE24.
  • PE22 does not copy BUM1 traffic to the cross-network PW marked as BDF PW, so PE23 will not receive the BUM1 traffic of CE11 sent by PE22.
  • PE23 receives the BUM1 traffic replicated by PE21 through the cross-network DF PW, according to the general rules of VPLS, it only forwards the BUM1 traffic to the AC port used to connect to CE12, and no longer replicates to other PWs. Similar to the operation of PE23, after receiving the BUM1 traffic copied by PE22 through the cross-network DF PW, PE24 only forwards the BUM1 traffic to the AC port used to connect to CE12.
  • PE25 After receiving the BUM1 traffic copied by PE21, it sends the BUM1 traffic to the AC port used to access CE15 on the EVPN side according to the general rules of EVPN, while on the VPLS side it follows the general rules of VPLS. According to the rules, there is no need to forward BUM1 traffic to PE23 and PE24 connected by ordinary PW.
  • the BUM1 traffic sent from CE11 will be sent from the forwarding path CE11-PE21-PE23 to CE12, and CE13 will be forwarded through CE11-PE21-PE22-PE24
  • the path receives the BUM1 traffic of CE11, thereby ensuring that the BUM1 traffic is sent to CE12 or CE13 through the only link on PE23, so that the traffic does not jump when it is sent from the EVPN side to the CE device on the VPLS side.
  • CE devices CE14, CE15, and CE16 on the EVPN side can also receive the BUM1 traffic sent by CE11 based on the general rules of EVPN, and ultimately ensure the normal operation of the service.
  • CE11 Since CE11 is in a dual-homing mode, in some cases, for example, CE11 can randomly decide whether to send BUM traffic to PE21 or PE22 through a hash algorithm or other algorithms. In this case, the specific replication and forwarding process can be seen in Figure 5b.
  • PE22 receives the BUM2 traffic sent from the AC port of CE11, and replicates the traffic to the VPLS side following the rules R505 and R510, that is, replicates to PE24 via DF PW, but will not connect to it via BDF PW. Copy of PE23. After PE21 receives the BUM2 traffic copied to it by PE22, it follows rule R520 when copying traffic to the VPLS side.
  • PE25 After PE25 receives the BUM2 traffic copied to it by PE22, since it belongs to the ordinary EVPN Peer, according to the general rules of EVPN, it only replicates the traffic to the AC port used to connect to CE15 on PE25.
  • PE23 After PE23 receives the BUM2 traffic sent by PE21, it replicates the BUM2 traffic to the AC port on PE23 used to connect to CE12. Similar to the operation of PE23, after receiving the BUM2 traffic sent by PE22, PE24 replicates the BUM2 traffic to the AC port on PE24 that is used to connect to CE13. Since the forwarding process is similar to the aforementioned process of receiving BUM2 traffic by PE21 first, it will not be repeated here.
  • CE12 on the VPLS side receives BUM2 traffic via the forwarding path CE11-PE22-PE21-PE23, and CE13 receives BUM2 traffic via CE11-PE22-PE24.
  • PE25 on the EVPN side receives the BUM3 traffic sent by CE15, the flow replication and forwarding process of the entire network is shown in Figure 5c. Since PE25 is a normal EVPN Peer, the general rules of EVPN should be applied. At this time, PE25 copies BUM3 traffic to EVPN Peer PE21 and PE22, and PE23 and PE24 connected via PW.
  • the PE21 After the PE21 receives the traffic copied by the PE25, it follows the copy rule R515, that is, the BUM3 traffic entered by the ordinary EVPN Peer PE25 is only copied to the ACs of CE11 and CE14 connected to it, and will not go through any cross-network PW, that is, DF PW and BDF PW connected to PE23, and DF PW and BDF PW connected to PE24 replicate traffic. Similar to the operation of PE21, when PE22 receives the BUM3 traffic sent by PE25, it will only replicate it to the AC port connected to CE16.
  • PE23 and PE24 will only receive BUM3 traffic from PE25, but not BUM3 traffic from PE21 or PE22, thereby ensuring that PE23 and PE24 will not jump.
  • PE23 and PE24 After PE23 and PE24 receive the BUM3 traffic, they follow the rule R525, that is, the BUM3 traffic received from the cross-network PW is only replicated to the AC port. Therefore, they respectively replicate the BUM3 traffic to the AC port of CE12 or CE13 connected to them, instead of Copy traffic to any cross-network PW.
  • Figure 5d shows the replication and forwarding process of the BUM4 traffic sent from the CE12 on the VPLS side.
  • the BUM4 traffic sent from CE12 reaches PE23 and is copied to all PWs.
  • PE21, PE22, PE24, and PE25 all receive BUM4 traffic.
  • PE21 receives the BUM4 traffic through the cross-network PW, it replicates the traffic to the AC port of CE14 connected to it according to rule R525, and because its connection with CE11 is marked as DF, it also replicates the traffic to the AC port of CE11.
  • PE22 After PE22 receives the BUM4 traffic through the cross-network PW, it copies the traffic to the AC port of CE16 according to the rule R525, but because its connection with CE11 is marked as BDF, combined with the general rules of EVPN, it no longer copies the BUM4 traffic to CE11 To avoid generating loops.
  • PE25 After PE25 receives the BUM4 traffic copied by PE23, it will only copy the traffic to CE15 on the EVPN side according to the general rules of EVPN, and on the VPLS side according to the general rules of the VPLS common PW, that is, adopt the full-mesh networking mode, PE25 No more traffic will be copied to other PWs.
  • the PE24 device on the same VPLS side After receiving the BUM4 traffic forwarded by PE23, the PE24 device on the same VPLS side directly copies the BUM4 traffic to the AC port of CE13. According to the general rules of VPLS ordinary PW, PE24 will no longer send BUM4 traffic to the PW connected to it to prevent loops.
  • the PW is a normal mode PW, and the forwarded traffic is unicast traffic.
  • the unicast traffic is defined for the second scenario to determine the forwarding path between the EVPN side and the VPLS side based on the MAC address learning rules, and the MAC address learning rules are as follows:
  • R605 multi-homed PE learns MAC from DF PW
  • R610 multi-homed PE does not learn MAC from BDF PW;
  • R615 multihomed PE learns MAC from DF PW, it will synchronize to EVPN Peer; add cross-network PW mark;
  • the R620 EVPN Peer After the R620 EVPN Peer discovers the MAC marked by the cross-network PW, if it finds the ESI tag value in the packet carrying the MAC locally, it points its MAC to the address of the PE that sent the packet; otherwise, discards the MAC.
  • the network structure shown in FIG. 3 is still taken as an example to analyze the forwarding situation of unicast traffic under the corresponding structure.
  • PE21 is a dual-homed PE device. Only PE21 learns MAC1 from PE23 via ESI1 DF PW, but does not learn MAC2 of PE24 from ESI2 BDF PW. Similar to the operation of PE21, PE22 learns MAC2 from PE24 through ESI2 DF PW, but does not learn MAC1 of PE23 from ESI1 BDF PW. According to the rule R615, after learning the MAC1 of PE23, the dual-homed PE21 sends the first packet carrying MAC1 to EVPN Peer PE22 and PE25 respectively, thereby synchronizing MAC1 to EVPN Peer PE22 and PE25.
  • the first message carries an ESI1 tag, and PE21 marks MAC1 as obtained via a cross-network PW. Similar to the operation after PE21 learns MAC1, MAC2 also synchronizes to EVPN Peer PE21 and PE25 through the second message sent by PE22.
  • the second message carries an ESI2 tag, and PE22 marks MAC2 as obtained via a cross-network PW.
  • the specific method of marking may be, for example, setting a flag bit in a message carrying MAC, or sending a notification message to notify, or any other feasible method, as long as the receiver can know that the received MAC is via The cross-network PW can be obtained.
  • EVPN Peer PE22 learns MAC1 and learns that MAC1 is obtained through the cross-network PW. At this time, the ESI tag value in the first packet carrying MAC1 is compared with the locally stored ESI value, and the same ESI tag value is found , Which is ESI1.
  • PE22 points its MAC to PE21, that is, the sender of the first packet.
  • PE21 learns MAC2 and learns that MAC2 is obtained through the cross-network PW. At this time, it compares the ESI tag value in the second packet carrying MAC2 with the ESI value stored locally, and finds that the same ESI2 tag exists.
  • PE21 points its MAC to PE22, that is, the sender of the second packet. Also according to rule R620, after learning the MAC1 or MAC2 address, PE25 knows that MAC1 and MAC2 are obtained through the cross-network PW, so it checks the locally stored ESI value, but it does not match the ESI1 or the ESI1 or MAC2 carried in the first packet. The ESI2 carried in the second packet is therefore discarded MAC1 and MAC2.
  • CE11 is dual-homed to PE21 and PE22.
  • PE21 queries its first MAC forwarding table and directly forwards it to PE23 through the cross-network ESI1 DF PW, and PE23 receives all the traffic.
  • PE23 receives all the traffic.
  • the first unicast traffic is described, it is sent to CE12.
  • PE22 queries its second MAC forwarding table and finds that the MAC sent to CE12 points to PE21, so it sends the second unicast traffic to PE21.
  • PE21 then queries the first MAC forwarding table, and then forwards it to PE23 through the cross-network ESI1 DF PW, and finally sends it to CE12.
  • the unicast traffic forwarding process sent from CE11 to CE13 is similar to the above process, and will not be repeated here.
  • PE23 queries its third MAC forwarding table and only finds the forwarding path to PE21. Therefore, the third unicast traffic can only reach CE11 through the forwarding path of CE12-PE23-PE21.
  • the R625 EVPN Peer After the R625 EVPN Peer discovers the MAC marked by the cross-network PW, if it finds that the local ESI value in the packet carrying the MAC is found, the BDF PW corresponding to the ESI value is set as the backup path.
  • Figure 6 shows a situation where PE21 and PE22 are dual-homed PEs and both have only dual-homed roles.
  • the multi-homed role may have When more than two PEs are mutually multi-homed PEs, furthermore, one or more PEs in the network can assume the roles of single-homed PE and multi-homed PE at the same time, and for the role of multi-homed PEs, they can even belong to multiple homes at the same time. There are different multi-homing PE groups.
  • the situation shown in FIG. 6 does not constitute the only limitation to the embodiment of the present invention.
  • ESI values stored locally by the PE there are also multiple ESI values stored locally by the PE.
  • any feasible search or matching algorithm can be used to determine the packet received by the PE Whether the carried ESI tag value is the same as any of the multiple ESI values stored locally.
  • the rules R605-R620 can be used to realize the MAC address learning and normalization of unicast traffic. Forward.
  • PW redundancy protection group is a PW protection mechanism that can be used in the VPLS scenario.
  • PW redundancy protection group By deploying multiple devices in the same group of services for redundancy protection, the switching efficiency of device failures is improved and the loss of services is reduced.
  • PW redundancy protection group mode it is necessary to ensure that only one of the group of PWs forming a redundant backup is in the working state, and the others are in the standby state.
  • the PW redundancy protection group usually includes two modes, namely, a master/slave (English: Master/Slave) mode and an independent (English: Independent) mode.
  • a master/slave (English: Master/Slave) mode the local determines the active and standby PWs and informs the remote end through the signaling protocol.
  • the remote PE can perceive the active and standby status.
  • the active and standby relationship between the PW side and the AC side does not affect each other, and the PW side can be realized Isolated from AC side faults.
  • the independent mode the active/standby status of the local PW is determined by the negotiation result of the remote AC side, and the remote end notifies the active/standby status to the local.
  • the protection switching caused by a fault on the AC side will affect the simultaneous protection switching on the PW side, and fault isolation cannot be achieved.
  • the working PW in the PW redundancy protection group is called the primary PW (English: Primary PW), and it is set to be preferentially used for traffic forwarding.
  • Other PWs in the standby state are called secondary PWs (English: Secondary PW), which are not used for traffic forwarding when the primary PW is working normally, but can be configured to receive traffic.
  • the primary PW and the backup PW can be determined by the forwarding priority configuration parameters of the PW, where the highest priority PW serves as the primary PW.
  • the local device In the Master/Slave mode, the local device can determine the active and standby PWs through the forwarding priority configuration parameters. However, in the independent mode, the local PW forwarding status is not determined by the forwarding priority configuration parameter, but is determined based on the forwarding status learned by the remote end.
  • the multi-homing PE on the EVPN side may also be connected to the PE on the VPLS side in the form of a PW redundancy protection group.
  • PE21 and PE22 are dual-homed PEs, and PE23 is connected to the two PWs of PE21 and PE22 to form a PW redundancy protection group PWRG1.
  • PE24 is connected to the two PWs of PE21 and PE22 to form a PW redundancy protection group PWRG2.
  • PWRG2 PW redundancy protection group
  • the standby PW can be configured to receive traffic, that is, the PW in the same group supports the multi-receiving mode.
  • the active and backup PW supports dual-receiving mode. Therefore, still taking the network structure shown in FIG. 3 as an example, based on whether PWRG1 and/or PWRG2 support dual reception, and whether the forwarded traffic type is BUM traffic or unicast traffic, the following continues to be divided into four different scenarios for description.
  • the PWs of multiple PEs form a PW redundancy protection group and do not support dual receiving, and the forwarded traffic is BUM traffic.
  • the replication and forwarding rules between the EVPN side and the VPLS side are as follows:
  • the traffic that R705 enters from the AC port can be copied to the cross-network DF PW;
  • R710 traffic that enters through the AC port is not copied to the cross-network BDF PW;
  • the traffic received by the R725 cross-network PW is copied to the AC port and the multi-homed PE, and the ESI tag is carried when it is copied to the multi-homed PE;
  • the R730 multihomed PE After the R730 multihomed PE receives the traffic carrying the ESI label, it only replicates to the AC port.
  • PE21 After PE21 receives BUM5 traffic via cross-network PW ESI1 DF PW, it copies it to the AC port of the CE device connected to it.
  • PE21 is the DF device connected to CE11. Therefore, BUM5 Traffic can be copied from PE21 to CE11 and CE14.
  • PE21 can also replicate to its dual-homed PE22, and needs to carry an ESI1 tag in the BUM5 traffic.
  • rule R730 after receiving BUM5 traffic, PE22, which is dual-homed to PE21, finds that the traffic carries the ESI1 label, so it only replicates to the AC port of the CE device connected to it.
  • PE22 as a BDF can no longer replicate BUM5 traffic to CE11. Therefore, BUM5 traffic can only be replicated from PE22 to CE16.
  • the replication and forwarding process of the above BUM5 traffic from CE12 can be seen in Figure 7.
  • PE24 is connected with dual-homing PE21 and PE22 in the form of PW redundancy protection group, its BUM traffic also adopts a similar replication and forwarding process.
  • the PW of the multi-homed PE forms a PW redundancy protection group and does not support dual receiving, and the forwarded traffic is unicast traffic.
  • the forwarding path between the EVPN side and the VPLS side is determined based on the MAC address learning rules, and the MAC address learning rules are as follows:
  • R805 multi-homed PE learns MAC from DF PW
  • R810 multi-homed PE does not learn MAC from BDF PW;
  • R815 multi-homed PE learns MAC from DF PW, it synchronizes to EVPN Peer; adds cross-network PW mark;
  • the R820 EVPN Peer After the R820 EVPN Peer discovers the MAC marked by the cross-network PW, if it finds the ESI tag value in the packet carrying the MAC locally, it points its own MAC to the address of the PE that sent the packet; otherwise, discards the MAC.
  • this scenario 4 may further include the rule R825 EVPN Peer. After discovering the MAC marked by the cross-network PW, if the local ESI value in the packet carrying the MAC is found, the ESI The BDF PW corresponding to the value is set as the backup path.
  • the PWs of multiple home PEs form a PW redundancy protection group and support dual receiving, and the forwarded traffic is BUM traffic.
  • the replication and forwarding rules between the EVPN side and the VPLS side are as follows:
  • the traffic that R905 enters through the AC port can be copied to the cross-network DF PW;
  • the traffic that enters the R910 through the AC port can be copied to the cross-network BDF PW;
  • the traffic received by R925 across the network PW is copied to the AC port and the multi-homed PE, and the ESI tag is carried when it is copied to the multi-homed PE;
  • the R930 multi-homed PE After the R930 multi-homed PE receives the traffic carrying the ESI label, it only replicates to the AC port.
  • rule R920 is set so that PE21 or PE22 no longer forward the BUM traffic copied from each other, thereby avoiding loops.
  • rules R915 and R925-R930 and the rules R715 and R725-R730 defined in scenario three the application methods are the same, so they will not be repeated here. If the PWs of PE21 and PE22 respectively connected to PE24 also form a PW redundancy protection group and support dual reception, the BUM traffic forwarding process sent to PE24 is the same as that of PE23.
  • the PWs of multiple home PEs form a PW redundancy protection group and support dual receiving, and the forwarded traffic is unicast traffic.
  • the unicast traffic determines the forwarding path between the EVPN side and the VPLS side based on the MAC address learning rules, and the MAC address learning rules are as follows:
  • R1005 multi-homed PE learns MAC from DF PW
  • R1010 multi-homed PE learns MAC from BDF PW
  • R1015 multihomed PE learns MAC from DF PW, it synchronizes to EVPN Peer; adds cross-network PW mark;
  • the R1020 EVPN Peer After the R1020 EVPN Peer discovers the MAC marked by the cross-network PW, if it finds the ESI tag value in the packet carrying the MAC locally, it points its own MAC to the address of the PE that sent the packet; otherwise, discards the MAC.
  • FIG. 3 includes at least (1) two PWs respectively connected to PE23 by dual-homed PE21 and PE22; (2) two PWs respectively connected to PE24 by dual-homed PE21 and PE22.
  • the PW mode of the above two groups of PWs (1) and (2) can be the same or different combinations selected from ordinary PW, PW redundancy protection group without supporting dual reception, and PW redundancy protection group supporting dual reception .
  • the PWs of the (1) and (2) groups are respectively applicable to corresponding replication rules according to the determined PW mode type and traffic type.
  • the PW connection of dual-homed PE21 and PE22 and PE23 is a redundant protection group but does not support dual-receiving mode.
  • the PW connection of dual-homed PE21, PE22 and PE24 is a redundant protection group and supports dual-receiving mode.
  • the above two redundant protection groups Set the PW connection of the PE21 device to DF PW.
  • BUM6 traffic is The dual-homed PE21 replicates to ESI1 DF PW. Since the ESI2 DF PW between PE21 and PE24 supports dual-receiving mode, refer to rule R920, BUM6 traffic is not replicated to ESI2 DF PW on dual-homed PE21.
  • Fig. 10 is a schematic diagram of a network device 500 provided according to an embodiment of the present application.
  • the network device 500 may be, for example, the PE device PE21 or PE22 on the EVPN side in FIG. 3, and may be used to execute the method shown in FIG. 4.
  • the network device 500 includes a memory 501, a processor 502, and a network interface 503.
  • the network interface 503 is configured to receive traffic forwarded by other PE devices or send the traffic to other PE devices according to forwarding rules.
  • the network interface 503 may be an Ethernet network port.
  • the memory 501 is used to store computer-readable instructions.
  • the processor 502 is configured to call the computer-readable instructions to execute: the network device and multiple other network devices run EVPN, wherein the network device as a PE device and at least one PE in the EVPN form a target Multi-homing structure of CE equipment or terminal equipment;
  • the data flow is forwarded through the network interface 503, where the conditions include: (1) being sent by other PE devices via the cross-network PW of the network device, ( 2) It needs to be forwarded by the network device to the PE device connected via the cross-network PW, and/or (3) includes the mark of the cross-network PW.
  • Network equipment PE21 runs EVPN with other network equipment PE22 and PE25, which forms a dual-homing structure for CE11 with PE22, and is connected to PE23 and PE24 in VPLS respectively through cross-network PWs.
  • the cross-network PWs may be ordinary PW mode.
  • PE21 receives the unicast traffic sent by PE22.
  • PE22 learns the MAC route of PE24 through the cross-network PW ESI2 DF PW in the normal PW mode, and after learning the MAC route of PE24, adds a cross-network PW mark for the MAC route. Therefore, when PE21 receives the unicast traffic sent by PE22, it will find that the unicast traffic includes the cross-network PW mark, which meets the above condition (3). At this time, PE21 follows the MAC learning and forwarding rules determined by the cross-network PW Forward the unicast traffic to PE23.
  • the network interfaces used to receive and forward data traffic can be the same or different.
  • the embodiment of the present application also provides a traffic forwarding system 600, which may be, for example, the network system structure shown in FIG. 3.
  • the system 600 includes multiple first PE devices, the multiple first PE devices are EVPN devices, and the multiple first PE devices form a multi-homing structure for one CE device or terminal device.
  • EVPN devices PE21 and PE22 in Figure 3 form a dual-homing structure for CE11 devices.
  • Each first PE device in the multi-homing structure is connected to the same at least one second PE device through a cross-network PW, and the second PE device is a VPLS device.
  • the dual-homing structure PE21 and PE22 in Figure 3 are connected to the VPLS devices PE23 and PE24 in pairs through the cross-network PW respectively.
  • the first PE device receives data traffic
  • the first PE device forwards the data flow according to the result of matching the data flow with the following conditions, where the conditions include:
  • CE12 Take the CE device CE12 on the VPLS side in Figure 3 sending BUM traffic to the CE device CE11 on the EVPN side as an example.
  • CE12 sends the BUM traffic
  • the VPLS device PE23 forwards the BUM traffic to PE21 via the PW connected to it based on the general forwarding rules of VPLS, and the PW is specifically in the cross-network PW mode, that is, PE21 as the first PE device finds that PE23 passes through PE21 Sending the BUM traffic across the network PW meets the aforementioned condition (3), so the PE21 continues to forward the BUM traffic according to the rules determined by the cross network PW.
  • the embodiment of the present application also provides another traffic forwarding system 700, as shown in FIG. 11.
  • the system 700 includes:
  • the first connecting unit 705 is configured to operate the Ethernet virtual private network EVPN between the first network device and multiple other network devices in the network, where the first network device serves as at least one of the operator edge PE device and the EVPN PE forms a multi-homing structure for a customer edge CE device or terminal device;
  • the second connecting unit 710 is configured to connect the first network device and at least one PE in the virtual private local area network VPLS through a cross-network pseudowire PW;
  • the receiving unit 715 is configured to receive data traffic by the first network device
  • the matching unit 720 is configured for the first network device to forward the data flow according to the matching result of the data flow with the following conditions, where the conditions include:
  • cross-network PW replication rules and traffic forwarding process that are specifically applicable to the network device 500, the traffic forwarding system 600, or the traffic forwarding system 700 when the above conditions are met can be referred to scenarios 1 to 6 in the above method embodiment, which will not be repeated here.
  • the embodiment of the present application also provides a computer-readable storage medium or computer program product, which is used to store a computer program, and the computer program is used to execute the above-mentioned traffic forwarding method 400.
  • the function implemented by the processor 501 may be an integrated logic circuit of hardware or completion of instructions in the form of software, such as a central processing unit CPU, or other general-purpose processors or digital signal processors.
  • DSP application-specific integrated circuit ASIC
  • ready-made programmable gate array FPGA or other programmable logic devices discrete gate or transistor logic devices, discrete hardware components, etc.
  • the general-purpose processor may be a microprocessor or the processor may also be any conventional processor or the like.
  • the traffic transceiving function implemented by the network interface 501 may be completed by an independent unit, or may further include, for example, a receiving subunit and a sending subunit, which are used to implement traffic reception and forwarding, etc. , There is no specific limitation here.
  • the size of the sequence number of each process does not mean the order of execution.
  • the execution order of each process should be determined by its function and internal logic, and should not be implemented in the embodiments of the present application.
  • the process constitutes any limitation.
  • modules and method steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professional technicians can use different methods for each specific application to realize the described functions.
  • the computer program product includes one or more computer instructions.
  • the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.
  • the computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center.
  • the computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or a data center integrated with one or more available media.
  • the usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (SSD)).

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Computer Security & Cryptography (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

一种在EVPN和VPLS共存双活网络中的流量转发方法和设备，所述网络包括由EVPN侧的多个PE设备构成的一组多归PE，所述一组多归PE均与VPLS侧的同一个PE设备通过跨网络PW相连接。所述跨网络PW用于流量在EVPN侧的所述一组多归PE和VPLS侧的PE设备之间转发，所述转发基于所述跨网络PW而满足一定的预设规则。通过本申请的方法，能够实现EVPN和VPLS共存双活网络中数据流量的正常转发，保证业务运行的可靠性和稳定性。

Description

EVPN和VPLS共存双活的方法、设备及系统
本申请要求于2019年8月22日提交中国专利局、申请号为CN 201910779880.X、发明名称为“EVPN和VPLS共存双活的方法、设备及系统”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请实施例涉及通信技术领域，特别涉及一种以太网虚拟私有网(英文：Ethernet Virtual Private Network，EVPN)和虚拟专用局域网(英文：Virtual Private Lan Service，VPLS)共存双活的方法、设备和系统。
背景技术
VPLS属于二层分组承载技术，本质上是一种基于互联网协议/多协议标签交换(英文：Internet Protocol/Multiprotocol Label Switching，IP/MPLS)和以太网技术的二层虚拟专用网(英文：Layer 2 Virtual Private Network，L2VPN)技术。VPLS技术的核心思想是利用信令协议在VPLS实例中的运营商边缘(Provider Edge,PE)设备之间建立及维护伪线PW(英文：Pseudo Wire，PW)，将二层协议帧封装后在PW上进行传输和交换。PW是分组交换网(英文：Packet-Switched Network，PSN)中采用二层技术建立的一对设备之间的仿真点对点双向连接。运营商通过PE和互联PW在PSN上传送客户不同区域LAN之间的业务数据流，由此将客户分布于不同区域的多个LAN互联成为一个仿真的LAN，称之为一个VPLS实例，每个区域的LAN可视为该仿真局域网的一个网段。
EVPN(Ethernet Virtual Private Network,EVPN)网络能够在一定程度上解决VPLS技术中的一些问题。EVPN是一种基于MPLS二层网络的VPN技术，其使用边界网关协议(英文：Border Gateway Protocol,BGP)作为控制平面的协议，实现PE设备之间的媒体接入控制(英文：Media Access Control，MAC)地址学习，将MAC地址学习和发布过程从传统的数据平面转移到控制平面，从而大幅减少了流量洪泛方式的MAC地址扩散，以及可以支持用户边缘(英文：Customer Edge，CE)设备多归属接入EVPN，以便于管理MAC地址实现负载分担。在EVPN网络中，PE设备之间无需再通过PW连接，而CE设备可通过多种接入方式与PE设备相连，EVPN方案的重要优势之一是实现了CE设备的多归属接入。所述CE设备多归属接入EVPN包括通过以太链路多归接入EVPN，即一个CE设备通过多条链路分别连接到多个网络侧设备。
发明内容
本申请实施例提供了一种报文处理方法、设备及系统，用于解决现有技术EVPN和VPLS共存双活网络中流量无法正常转发的技术问题。通过执行所述方法能够实现EVPN 和VPLS网络之间的有效对接，保证业务的正常运行。
第一方面，本申请实施例提供了一种流量转发方法，在该方法中第一网络设备与网络中的多个其他网络设备运行EVPN，其中所述第一网络设备作为PE设备与所述EVPN中的至少一个PE形成针对一个CE设备或终端设备的多归结构；与处于VPLS中的至少一个PE通过跨网络PW相连接；接收数据流量；根据所述数据流量与以下条件的匹配结果，对所述数据流量进行转发，其中，所述条件包括：(1)由其他PE设备经由所述第一网络设备的跨网络PW发送，(2)需要由所述第一网络设备转发至经由跨网络PW连接的PE设备，和/或(3)包括跨网络PW的标记。
上述技术方案中，考虑传统VPLS设备的PW模式类型，连接所述第一网络设备的跨网络PW的模式可以为普通PW、PW保护组且不支持双收、或PW保护组且支持双收的模式。所述流量可以为多播BUM流量或单播流量。在一种可能的设计中，对于连接所述一组多归结构PE的多个跨网络PW，其中一个跨网络PW可以作为指定转发DF PW，其余的跨网络PW可以作为备用指定转发BDF PW，以保证EVPN侧的多归结构PE在向VPLS侧的PE设备转发流量时转发路径的确定性。
上述技术方案中，当数据流量与相应的条件匹配时，可以具体按照以下转发规则转发所述数据流量。
当跨网络PW的模式为普通PW，并且转发流量为BUM流量时，所述第一网络设备基于以下规则转发所述BUM流量：由AC口进入的流量可以向跨网络DF PW复制；由AC口进入的流量不向跨网络BDF PW复制；由普通EVPN对等体EVPN Peer进入的流量不向跨网络PW复制；由多归PE进入的流量向跨网络DF PW复制；跨网络PW接收到的流量只向AC口复制；其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
当跨网络PW模式为普通PW，并且转发流量为单播流量时，所述第一网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：多归PE从DF PW学习MAC；多归PE不从BDF PW学习MAC；多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
当跨网络PW模式为PW保护组且不支持双收，并且转发流量为BUM流量时，所述第一网络设备基于以下规则转发所述BUM流量：由AC口进入的流量可以向跨网络DF PW复制；由普通EVPN Peer进入的流量不向跨网络PW复制；由多归PE进入的流量向跨网络DF PW复制；跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；多归PE接收到携带ESI标签的流量后，只向AC口复制；其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
在一种可能的设计中，当跨网络PW模式为PW保护组且不支持双收，并且转发流量为BUM流量时，还可以包括以下转发规则：由AC口进入的流量不向跨网络BDF PW复制。由此能够节约转发流量的开销，节省流量转发带宽。
当跨网络PW模式为PW保护组且不支持双收，并且转发流量为单播流量时，所述第一网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：多归PE从DF PW学习MAC；多归PE不从BDF PW学习MAC；多归PE从DF PW学习MAC后， 同步到EVPN Peer，增加跨网络PW标记；EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
当跨网络PW模式为PW保护组且支持双收，并且转发流量为BUM流量时，所述第一网络设备基于以下规则转发所述BUM流量：由AC口进入的流量可以向跨网络DF PW复制；由AC口进入的流量可以向跨网络BDF PW复制；由普通EVPN Peer进入的流量不向跨网络PW复制；由多归PE进入的流量不向跨网络DF PW复制；跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；多归PE接收到携带ESI标签的流量后，只向AC口复制；其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
当跨网络PW模式为PW保护组且支持双收，并且转发流量为单播流量时，所述第一网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：多归PE从DF PW学习MAC；多归PE从BDF PW学习MAC；多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
通过设定、匹配和使用上述针对不同流量类型的跨网络PW的转发规则及MAC学习规则，能够实现EVPN和VPLS共存双活网络中EVPN侧和VPLS的有效对接，避免VPLS设备在接收流量时形成跳变，从而保证业务的正常运行。
在一种可能的设计中，对于跨网络PW为普通PW、PW保护组且不支持双收、或PW保护组且支持双收的模式，在转发单播流量时所述第一网络设备学习MAC地址的规则还进一步包括：EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI值，则将该ESI值对应的BDF PW设置为备份路径。当转发单播流量的主路径不可用时，可以使用备份路径完成单播流量的转发，由此提高网络通信的健壮性和安全性。
在一种可能的设计中，为MAC地址增加跨网络PW标记的方式为新增MAC扩展团体属性，通过字段Flags标记并区分跨网络PW的具体类型；或者，复用已有的MAC迁移属性，使用字段Flags的空余位标记并区分PW的具体类型。
第二方面，本申请实施例提供了一种网络设备，所述网络设备包括：存储器，用于存储计算机可读指令；以及处理器，用于调用所述计算机可读指令，以执行：所述网络设备与多个其他网络设备运行EVPN，其中所述网络设备作为运营商边缘PE设备与所述EVPN中的至少一个PE形成针对一个CE设备或终端设备的多归结构；与处于VPLS中的至少一个PE通过跨网络PW相连接；接收数据流量；根据所述数据流量与以下条件的匹配结果，对所述数据流量进行转发，其中，所述条件包括：(1)由其他PE设备经由所述网络设备的跨网络PW发送，(2)需要由所述网络设备转发至经由跨网络PW连接的PE设备，和/或(3)包括跨网络PW的标记。
上述技术方案中，考虑传统VPLS设备的PW模式类型，连接所述网络设备的跨网络PW的模式可以为普通PW、PW保护组且不支持双收、或PW保护组且支持双收的模式。所述流量可以为多播BUM流量或单播流量。在一种可能的设计中，对于连接所述一组多归结构PE的多个跨网络PW，其中一个跨网络PW可以作为指定转发DF PW，其余的跨 网络PW可以作为备用指定转发BDF PW，以保证EVPN侧的多归结构PE在向VPLS侧的PE设备转发流量时转发路径的确定性。
上述技术方案中，当数据流量与相应的条件匹配时，可以具体按照以下转发规则转发所述数据流量。
当跨网络PW的模式为普通PW，并且转发流量为BUM流量时，所述网络设备基于以下规则转发所述BUM流量：由AC口进入的流量可以向跨网络DF PW复制；由AC口进入的流量不向跨网络BDF PW复制；由普通EVPN对等体EVPN Peer进入的流量不向跨网络PW复制；由多归PE进入的流量向跨网络DF PW复制；跨网络PW接收到的流量只向AC口复制；其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
当跨网络PW模式为普通PW，并且转发流量为单播流量时，所述网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：多归PE从DF PW学习MAC；多归PE不从BDF PW学习MAC；多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
当跨网络PW模式为PW保护组且不支持双收，并且转发流量为BUM流量时，所述网络设备基于以下规则转发所述BUM流量：由AC口进入的流量可以向跨网络DF PW复制；由普通EVPN Peer进入的流量不向跨网络PW复制；由多归PE进入的流量向跨网络DF PW复制；跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；多归PE接收到携带ESI标签的流量后，只向AC口复制；其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
在一种可能的设计中，当跨网络PW模式为PW保护组且不支持双收，并且转发流量为BUM流量时，还可以包括以下转发规则：由AC口进入的流量不向跨网络BDF PW复制。由此能够节约转发流量的开销，节省流量转发带宽。
当跨网络PW模式为PW保护组且不支持双收，并且转发流量为单播流量时，所述网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：多归PE从DF PW学习MAC；多归PE不从BDF PW学习MAC；多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
当跨网络PW模式为PW保护组且支持双收，并且转发流量为BUM流量时，所述网络设备基于以下规则转发所述BUM流量：由AC口进入的流量可以向跨网络DF PW复制；由AC口进入的流量可以向跨网络BDF PW复制；由普通EVPN Peer进入的流量不向跨网络PW复制；由多归PE进入的流量不向跨网络DF PW复制；跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；多归PE接收到携带ESI标签的流量后，只向AC口复制；其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
当跨网络PW模式为PW保护组且支持双收，并且转发流量为单播流量时，所述第一网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：多归PE从 DF PW学习MAC；多归PE从BDF PW学习MAC；多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
通过设定、匹配和使用上述针对不同流量类型的跨网络PW的转发规则及MAC学习规则，能够实现EVPN和VPLS共存双活网络中EVPN侧和VPLS的有效对接，避免VPLS设备在接收流量时形成跳变，从而保证业务的正常运行。
在一种可能的设计中，对于跨网络PW为普通PW、PW保护组且不支持双收、或PW保护组且支持双收的模式，在转发单播流量时所述网络设备学习MAC地址的规则还进一步包括：EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI值，则将该ESI值对应的BDF PW设置为备份路径。当转发单播流量的主路径不可用时，可以使用备份路径完成单播流量的转发，由此提高网络通信的健壮性和安全性。
在一种可能的设计中，为MAC地址增加跨网络PW标记的方式为新增MAC扩展团体属性，通过字段Flags标记并区分跨网络PW的具体类型；或者，复用已有的MAC迁移属性，使用字段Flags的空余位标记并区分PW的具体类型。
第三方面，本申请实施例提供了一种流量转发系统，所述系统包括多个第一运营商边缘PE设备，所述多个第一PE设备为EVPN设备，并且所述多个第一PE设备形成针对一个客户边缘CE设备或终端设备的多归结构；所述多归结构中的每个第一PE设备均与相同的至少一个第二PE设备通过跨网络伪线PW相连接，所述第二PE设备为VPLS设备；所述第一PE设备接收数据流量；所述第一PE设备根据所述数据流量与以下条件的匹配结果，对所述数据流量进行转发，其中，所述条件包括：(1)由其他PE设备经由所述网络设备的跨网络PW发送，(2)需要由所述网络设备转发至经由跨网络PW连接的PE设备，和/或(3)包括跨网络PW的标记。
上述技术方案中，考虑传统VPLS设备的PW模式类型，连接所述第一PE设备的跨网络PW的模式可以为普通PW、PW保护组且不支持双收、或PW保护组且支持双收的模式。所述流量可以为多播BUM流量或单播流量。在一种可能的设计中，对于连接所述一组多归结构PE的多个跨网络PW，其中一个跨网络PW可以作为指定转发DF PW，其余的跨网络PW可以作为备用指定转发BDF PW，以保证EVPN侧的多归结构PE在向VPLS侧的PE设备转发流量时转发路径的确定性。
上述技术方案中，当数据流量与相应的条件匹配时，可以具体按照以下转发规则转发所述数据流量。
当跨网络PW的模式为普通PW，并且转发流量为BUM流量时，所述第一PE设备基于以下规则转发所述BUM流量：由AC口进入的流量可以向跨网络DF PW复制；由AC口进入的流量不向跨网络BDF PW复制；由普通EVPN对等体EVPN Peer进入的流量不向跨网络PW复制；由多归PE进入的流量向跨网络DF PW复制；跨网络PW接收到的流量只向AC口复制；其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
当跨网络PW模式为普通PW，并且转发流量为单播流量时，所述第一PE设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：多归PE从DF PW学习MAC；多归PE不从BDF PW学习MAC；多归PE从DF PW学习MAC后，同步到EVPN Peer， 增加跨网络PW标记；EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
当跨网络PW模式为PW保护组且不支持双收，并且转发流量为BUM流量时，所述第一PE设备基于以下规则转发所述BUM流量：由AC口进入的流量可以向跨网络DF PW复制；由普通EVPN Peer进入的流量不向跨网络PW复制；由多归PE进入的流量向跨网络DF PW复制；跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；多归PE接收到携带ESI标签的流量后，只向AC口复制；其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
在一种可能的设计中，当跨网络PW模式为PW保护组且不支持双收，并且转发流量为BUM流量时，还可以包括以下转发规则：由AC口进入的流量不向跨网络BDF PW复制。由此能够节约转发流量的开销，节省流量转发带宽。
当跨网络PW模式为PW保护组且不支持双收，并且转发流量为单播流量时，所述第一PE设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：多归PE从DF PW学习MAC；多归PE不从BDF PW学习MAC；多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
当跨网络PW模式为PW保护组且支持双收，并且转发流量为BUM流量时，所述第一PE设备基于以下规则转发所述BUM流量：由AC口进入的流量可以向跨网络DF PW复制；由AC口进入的流量可以向跨网络BDF PW复制；由普通EVPN Peer进入的流量不向跨网络PW复制；由多归PE进入的流量不向跨网络DF PW复制；跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；多归PE接收到携带ESI标签的流量后，只向AC口复制；其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
当跨网络PW模式为PW保护组且支持双收，并且转发流量为单播流量时，所述第一PE设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：多归PE从DF PW学习MAC；多归PE从BDF PW学习MAC；多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
通过设定、匹配和使用上述针对不同流量类型的跨网络PW的转发规则及MAC学习规则，能够实现EVPN和VPLS共存双活网络中EVPN侧和VPLS的有效对接，避免VPLS设备在接收流量时形成跳变，从而保证业务的正常运行。
在一种可能的设计中，对于跨网络PW为普通PW、PW保护组且不支持双收、或PW保护组且支持双收的模式，在转发单播流量时所述第一网络设备学习MAC地址的规则还进一步包括：EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI值，则将该ESI值对应的BDF PW设置为备份路径。当转发单播流量的主路径不可用时，可以使用备份路径完成单播流量的转发，由此提高网络通信的健壮性和安全性。
在一种可能的设计中，为MAC地址增加跨网络PW标记的方式为新增MAC扩展团体属性，通过字段Flags标记并区分跨网络PW的具体类型；或者，复用已有的MAC迁移属性，使用字段Flags的空余位标记并区分PW的具体类型。
第四方面，本申请实施例提供了一种流量转发系统，所述系统包括：第一连接单元，用于第一网络设备与网络中的多个其他网络设备运行以太网虚拟私有网EVPN，其中所述第一网络设备作为运营商边缘PE设备与所述EVPN中的至少一个PE形成针对一个客户边缘CE设备或终端设备的多归结构；第二连接单元，用于第一网络设备与处于虚拟专用局域网VPLS中的至少一个PE通过跨网络伪线PW相连接；接收单元，用于第一网络设备接收数据流量；匹配单元，用于第一网络设备根据所述数据流量与以下条件的匹配结果，对所述数据流量进行转发，其中，所述条件包括：(1)由其他PE设备经由所述第一网络设备的跨网络PW发送，(2)需要由所述第一网络设备转发至经由跨网络PW连接的PE设备，和/或(3)包括跨网络PW的标记。
上述技术方案中，考虑传统VPLS设备的PW模式类型，连接所述第一网络设备的跨网络PW的模式可以为普通PW、PW保护组且不支持双收、或PW保护组且支持双收的模式。所述流量可以为多播BUM流量或单播流量。在一种可能的设计中，对于连接所述一组多归结构PE的多个跨网络PW，其中一个跨网络PW可以作为指定转发DF PW，其余的跨网络PW可以作为备用指定转发BDF PW，以保证EVPN侧的多归结构PE在向VPLS侧的PE设备转发流量时转发路径的确定性。
上述技术方案中，当数据流量与相应的条件匹配时，可以具体按照以下转发规则转发所述数据流量。
当跨网络PW的模式为普通PW，并且转发流量为BUM流量时，所述第一网络设备基于以下规则转发所述BUM流量：由AC口进入的流量可以向跨网络DF PW复制；由AC口进入的流量不向跨网络BDF PW复制；由普通EVPN对等体EVPN Peer进入的流量不向跨网络PW复制；由多归PE进入的流量向跨网络DF PW复制；跨网络PW接收到的流量只向AC口复制；其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
当跨网络PW模式为普通PW，并且转发流量为单播流量时，所述第一网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：多归PE从DF PW学习MAC；多归PE不从BDF PW学习MAC；多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
当跨网络PW模式为PW保护组且不支持双收，并且转发流量为BUM流量时，所述第一网络设备基于以下规则转发所述BUM流量：由AC口进入的流量可以向跨网络DF PW复制；由普通EVPN Peer进入的流量不向跨网络PW复制；由多归PE进入的流量向跨网络DF PW复制；跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；多归PE接收到携带ESI标签的流量后，只向AC口复制；其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
在一种可能的设计中，当跨网络PW模式为PW保护组且不支持双收，并且转发流量为BUM流量时，还可以包括以下转发规则：由AC口进入的流量不向跨网络BDF PW复 制。由此能够节约转发流量的开销，节省流量转发带宽。
当跨网络PW模式为PW保护组且不支持双收，并且转发流量为单播流量时，所述第一网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：多归PE从DF PW学习MAC；多归PE不从BDF PW学习MAC；多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
当跨网络PW模式为PW保护组且支持双收，并且转发流量为BUM流量时，所述第一网络设备基于以下规则转发所述BUM流量：由AC口进入的流量可以向跨网络DF PW复制；由AC口进入的流量可以向跨网络BDF PW复制；由普通EVPN Peer进入的流量不向跨网络PW复制；由多归PE进入的流量不向跨网络DF PW复制；跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；多归PE接收到携带ESI标签的流量后，只向AC口复制；其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
当跨网络PW模式为PW保护组且支持双收，并且转发流量为单播流量时，所述第一网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：多归PE从DF PW学习MAC；多归PE从BDF PW学习MAC；多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
通过设定、匹配和使用上述针对不同流量类型的跨网络PW的转发规则及MAC学习规则，能够实现EVPN和VPLS共存双活网络中EVPN侧和VPLS的有效对接，避免VPLS设备在接收流量时形成跳变，从而保证业务的正常运行。
在一种可能的设计中，对于跨网络PW为普通PW、PW保护组且不支持双收、或PW保护组且支持双收的模式，在转发单播流量时所述第一网络设备学习MAC地址的规则还进一步包括：EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI值，则将该ESI值对应的BDF PW设置为备份路径。当转发单播流量的主路径不可用时，可以使用备份路径完成单播流量的转发，由此提高网络通信的健壮性和安全性。
在一种可能的设计中，为MAC地址增加跨网络PW标记的方式为新增MAC扩展团体属性，通过字段Flags标记并区分跨网络PW的具体类型；或者，复用已有的MAC迁移属性，使用字段Flags的空余位标记并区分PW的具体类型。
第五方面，本申请实施例提供了一种计算机可读存储介质或者计算机程序产品，用于存储计算机程序，该计算机程序用于执行第一方面任意可能的设计中的方法。
附图说明
为了更清楚地说明本申请实施例中的技术方案，下面将对实施例描述中所需要使用的附图作简单地介绍。
图1为现有技术中提供的一种VPLS网络结构示意图；
图2为本发明实施例提供的一种EVPN网络结构示意图；
图3为本申请实施例提供的一种流量转发方法的应用网络场景示意图；
图4为本申请实施例提供的一种流量转发方法的流程示意图；
图5a-5d为为本申请实施例提供的BUM流量的转发过程示意图；
图6为本申请实施例提供的一种单播流量的转发过程示意图；
图7为本申请实施例提供的另一种BUM流量的转发过程示意图；
图8为本申请实施例提供的另一种BUM流量的转发过程示意图；
图9a-9b为本申请实施例提供的MAC地址字段格式示意图；
图10为本申请实施例提供的一种网络设备的结构示意图。
图11为本申请实施例提供的一种流量转发系统的结构示意图。
具体实施方式
下面将结合附图，对本申请实施例中的技术方案进行描述。本申请实施例描述的网络架构以及业务场景是为了更加清楚的说明本申请实施例的技术方案，并不构成对于本申请实施例提供的技术方案的唯一限定。本领域普通技术人员可知，随着网络架构的演变和新业务场景的出现，本申请实施例提供的技术方案对于类似的技术问题，同样适用。
为了更加清楚地说明，首先对VPLS网络和EVPN网络涉及的一些工作原理及特性进行描述。
图1示出了在交互式网络电视(英文：Internet Protocol Television，IPTV)业务场景下采用VPLS网络结构的拓扑模型。光缆终端设备(Optical Line Terminal,OLT)作为客户边缘(Customer Edge,CE)设备，运营商在设备侧设置了多个接入VPLS业务的PE设备。OLT经接入电路(Attachment Circuit,AC)和相应的运营商边缘PE设备相连，各PE设备之间采用全网状连接伪线(英文：Full-mesh PW)相连，即各个PE设备之间通过PW两两相连。该组网模型同样适用于IPTV以外的其他业务。虽然VPLS由于有效结合了VPN、IP/MPLS和以太网交换等多种技术的特点，但在VPLS网络中，每个VPLS实例都需要在该实例中的n个PE设备之间建立全网状的标签转发路径(英文：Label Switched Path，LSP)隧道，数量为n×(n-1)/2条，这样一方面会产生大量的信令开销，另一方面PE设备要为每条配置的PW复制分组，处理负担较大，上述两个因素制约了VPLS组网规模。图2示出了一种示例性的EVPN网络的结构示意图。网络100包括服务商提供的骨干网和多个EVPN站点(英文：Site)。所述骨干网包括PE设备PE1、PE2和PE3以及多个骨干(英文：Provider，P)设备(图中未示出)。所述多个EVPN站点包括第一站点和第二站点，其中，第一站点和第二站点属于同一个EVPN1。CE4双归接入PE1和PE2，而CE5单归接入PE3。各个PE设备之间建立邻居关系后相互发送以太网段路由，根据所述以太网段路由中携带的以太网段落标识(英文：Ethernet Segment Identifier，ESI)的值。例如，对于图2示出的场景，PE1和PE2作为被CE4双归接入的设备，具有相同的ESI值—ESI1。在构建的EVPN网络中通常可以转发已知单播流量，也可以转发多播(英文：BUM)流量。所述已知单播流量也可以简称为单播流量，所述BUM流量一般包括广播流量、组播流量和未知目的地址的单播流量。当一台PE设备收到单播流量后，按照MAC地址表通过表项的出接口转发至下一跳；而当一台PE设备收到多播流量后，将多播流量在广播域内进行洪泛(英文：flood)。
在图2示出的EVPN网络场景中，由于PE1和PE2支持CE4的双归，此时，为了避免CE4从归属的PE1和PE2收到重复的BUM流量，从而造成网络带宽资源的浪费，EVPN引入了指定转发器(英文：Designated Forwarder，DF)选举机制，即从PE1和PE2中指定一个PE来转发BUM流量。作为一种可能的示例，PE1和PE2之间可以通过跨设备链路聚合(英文：Multi-Chassis Link Aggregation Group，MC-LAG)决策出主备设备。例如，图2中PE1即被选举为CE4的DF，也可以称为主设备，而PE2则作为备份DF(英文：Backup DF，BDF)，也可以称为从设备。此时，从CE5方向发来的BUM流量只从PE1向CE4转发，而作为BDF的PE2在PE1正常工作时不转发所述BUM流量。
在CE4设备双归组网中，可以配置EVPN组网的冗余模式，即配置与同一CE相连的各个PE的活跃模式为单活模式或多活模式。以太网链路可以处于活跃状态或者非活跃状态。活跃状态意味着该以太网链路可以用于转发数据流。所述单活模式是指只有一条以太网链路的状态是活跃的，其他的一条或者多条以太网链路的状态是非活跃的。所述多活模式是指以太网链路段中的部分以太网链路的状态是活跃的，另一部分以太网链路的状态是非活跃的。这些活跃状态的以太网链路可以实现对数据流进行负载分担地转发，从而提供更大带宽的传输能力。当主用以太网链路故障时，可以切换到备用以太网链路来转发数据流。
通过配置冗余模式可以控制CE双归组网是否对单播流量进行负载分担。例如图2中配置同时与CE4相连的PE1和PE2的活跃模式为双活模式，即CE4此时支持双归双活。这样，CE5在经由PE3向CE4发送单播流量时，会以负载分担的形式同时向PE1和PE2发送流量。并且，EVPN还支持别名(英文：Aliasing)功能。例如，在CE双归双活场景中，主设备PE能够学习到CE侧的MAC地址，而从设备PE可能由于某些原因学习不到CE侧的MAC地址，此时远端PE可以通过双归PE发来的以太自动发现路由(英文：Ethernet A-D Route)携带的ESI值来感知到CE侧的MAC地址可达性，这个功能被称为别名。如图2所示，PE1和PE2中仅有PE1向PE3发送了携带CE4侧MAC地址的MAC/IP地址通告路由(英文：MAC/IP Advertisement Route)，但是PE3可以通过Ethernet A-D Route携带的ESI值，即ESI1，能够感知到同样标记了ESI1值的PE2也可以到达CE4，即可以形成负载分担。
当CE4在双归双活模式下，即CE4双归属至PE1和PE2且使能了负载分担时，如果PE1和PE2之间建立了邻居关系，则当PE1从CE4收到了BUM流量后，PE1会将BUM流量转发至PE2。为了避免PE2继续将流量转发至CE4形成环路，EVPN中定义了水平分割功能，即在PE1收到来自CE4的BUM流量会转发给PE2，PE2收到报文后将检查流量中携带的EVPN ESI标签(英文：EVPN ESI Label)，发现该标签中的ESI值等于PE2与CE4连接的网段的ESI值，则PE2不会将该BUM流量发送至CE4，从而避免形成环路。
需要说明的是，上述CE4双归至PE1和PE2的情况仅作为示例。在实际应用场景中，CE也可以多归至多于两个PE设备，此时归属于同一CE设备的全部PE设备均被赋予相同的ESI值。并且，多归的PE设备可以设置成多活跃模式，从而相互之间形成负载分担。上述方式称为CE多归多活。此外，除CE设备外，也可以是其他设备类型多归属至多个PE设备，所述其他设备类型例如可以为终端设备。所述多归属包括双归属的情形，并且根据需要为多个PE设备设置多活跃模式或单活跃模式，这可以结合具体应用场景设定。无论哪种情形，当多归多活至多于两个PE设备时，其实现机制仍类似于双归双活模式。
当前，运营商网络中会涉及由VPLS网络向EVPN网络转换的问题。在某些特定场景下，运营商可能仅想对部分PE设备进行改造。以图1所示的IPTV业务类型作为示例，可能仅想将与OLT设备连接的PE设备侧，即左侧PE设备改造为支持EVPN，但不想修改IPTV侧，即右侧PE设备的配置。此时，如果只是简单的将左侧PE设备保留为采用VPLS PW机制传输数据，或者修改为采用EVPN机制传输数据均可能出现问题。例如，如果将左侧PE设备保留为PW机制，则右侧PE设备的BUM流量经过2个左侧PE设备，会在OLT设备上形成冗余；而如果在左侧PE设备采用EVPN机制，那么OLT发往IPTV侧的BUM流量会在右侧PE上不断跳变，从而导致各种可能的网络问题。本申请实施例描述的技术方案可以适用于EVPN和VPLS共存双活的网络中。图3示出了一种可能的EVPN和VPLS共存双活网络的场景。图3中运营商边缘设备PE21、PE22和PE25在网络改造后支持EVPN，而运营商边缘设备PE23和PE24仍保留为传统VPLS。此时，PE23和PE24之间需要建立VPLS PW联接，并且PE23和PE24需要分别与改造后的PE21、PE22和PE25建立VPLS PW联接。CE1双归至PE21和PE22，并且PE21和PE22设置为双活。同时为了更清楚地对本申请实施例进行阐述，作为区别于PE21和PE22的设备，在图3示出的场景中，PE25虽然改造为支持EVPN，但并不像PE21和PE22一样支持CE的双归双活，而是作为一般的支持EVPN的PE设备为CE15提供接入。PE21、PE22和PE25之间构成EVPN对等体(英文：EVPN Peer)。需要说明的是，本领域技术人员应该理解，图3所示的场景以及其后基于该场景所阐述的实施例的具体实现方式仅是一种例举，不应构成对本申请的限制。
在图3示出的场景中，仅选择采用单一EVPN或VPLS网络的数据传输机制，无法实现EVPN和VPLS共存双活网络中业务的正常运行。为此，本申请实施例首先定义一种跨网络PW模式，该模式的PW适用于EVPN侧的多归PE设备与VPLS侧的PE设备之间的PW连接，并需要满足一定的EVPN侧和VPLS侧之间的复制转发规则，保证EVPN侧和VPLS侧之间流量的正常转发。
所述EVPN侧和VPLS侧之间的复制转发规则是指当EVPN侧与VPLS侧的PE设备之间通信时所遵循的规则，而当仅EVPN侧内的PE相互通信，或仅VPLS侧的PE相互通信时，分别遵循EVPN或VPLS的一般性规则，以上解释适用于本申请的多个或全部实施例。
本申请实施例提供了一种流量转发方法400，所述方法400的流程如图4所示，具体包括以下内容。
S405第一网络设备与网络中的多个其他网络设备运行以太网虚拟私有网EVPN，其中所述第一网络设备作为运营商边缘PE设备与所述EVPN中的至少一个PE形成针对一个客户边缘CE设备或终端设备的多归结构；
S410与处于虚拟专用局域网VPLS中的至少一个PE通过跨网络伪线PW相连接；
S415所述第一网络设备接收数据流量。
S420所述第一网络设备根据所述数据流量与以下条件的匹配结果，对所述数据流量进行转发，其中，所述条件包括：
(1)由其他PE设备经由所述网络设备的跨网络PW发送，(2)需要由所述网络设备转发至经由跨网络PW连接的PE设备，和/或(3)包括跨网络PW的标记。
以图3中的PE21接收PE22发送的BUM流量，并转发所述BUM流量至CE12设备 为例。根据前述内容，PE21作为第一网络设备符合S405和S410所述的网络结构。根据所述S415，PE21接收由PE22设备发送的所述BUM流量。PE21确定所述BUM流量是否符合所述S410中的所述三个条件中的一个或多个。根据所述S420，PE21确定所述BUM流量需要经由ESI1 DF PW这一跨网络PW转发至PE23，以使得PE23再转发所述BUM流量至CE12，即符合S420中的条件(2)，此时PE21按照跨网络PW确定的转发规则向PE23转发所述BUM流量。需要说明的是，在整个EVPN和VPLS共存双活网络中，EVPN侧可以包括一组或多组多归PE，每组多归PE中的每一个PE设备均与VPLS侧的同一个PE设备通过PW相连，连接所述每组多归PE的PW均为跨网络PW模式。
以下，本申请实施例将结合几种具体的场景介绍跨网络PW的适用规则和流量转发过程。
在一种可能的设计中，对于EVPN和VPLS共存双活的网络，例如如图3所示的网络，用于连接EVPN侧和VPLS侧的PW类型为普通模式的PW，如全网状连接Full-mesh组网模式。在上述情形下，PE23实际上同时与PE21和PE22建立PW连接，也即对于PE21和PE22而言，其分别到PE23的PW实际构成一组双归PW。为了保证正常的业务转发，需要允许PE23发送流量至PE21和PE22时，PE21和PE22均可以处理。但由于CE11双归双活，则要求CE11的流量只能由PE21或PE22之一发往PE23，否则PE23接收CE11流量的路径不稳定，会导致VPLS侧的PE23形成跳变。在本申请实施例中，PE21与PE23、以及PE22与PE23之间的PW均被设置为跨网络模式PW，并为这两条PW设置相同的ESI值为ESI1，以标识其是双归的。类似地，将PE21与PE24，以及PE22与PE24之间的PW也均设置为跨网络模式PW，并为这两条PW设置相同的ESI值为ESI2。
基于流量类型是单播流量还是BUM流量，网络包括至少两种可能的场景，相应的流量处理方法如下。
场景一 PW为普通模式PW，转发流量为BUM流量。
为了便于理解，这里首先对单一EVPN网络中的BUM流量复制规则进行描述，本发明实施例称之为EVPN的一般性规则。对于单一的EVPN网络，PE设备在接收到某CE设备发出的BUM流量后，向所有本地连接的接入电路AC，以及与其相互交换报文消息的EVPN对端(英文：Peer)复制所述BUM流量。所述AC为CE设备或其他用户设备接入PE的链路，复制的流量可以通过所述AC发送至CE设备或其他用户设备。此时，对于接收到所述PE设备发送的所述BUM流量的另一PE设备，将所述BUM流量向所有本地连接的AC复制，而不再向其EVPN Peer复制。并且，所述另一PE设备在向AC复制所述BUM流量时，根据所述BUM流量中携带的ESI Label做水平分割处理，即当所述另一PE设备发现所述BUM流量中携带的ESI Label与其本地保存的ESI值相同，并且其被设置为该ESI值对应的BDF角色时，不再向相应的AC复制所述BUM流量。以图3示出的EVPN侧内的PE设备流量转发场景为例，PE21接收到CE11经由AC发送的BUM流量时，向用于接入CE14的AC口，以及作为其EVPN Peer的PE22及PE25复制所述BUM流量。PE22在接收到PE21发送的所述BUM流量后，向用于接入CE16的AC口复制所述BUM流量。而由于PE22发现自PE21接收的报文中的ESI Label与其本地保存的ESI值相同，因而不再向将其设置为ESI BDF的CE11对应的AC口复制所述BUM流量。
其次，对单一的VPLS网络中的BUM流量复制规则进行描述，本发明实施例称之为VPLS普通PW的一般性规则。对于单一的VPLS网络，PE设备将从CE设备接收的流量 转发至全部PW，但不转发从任何PE设备接收的流量，以避免造成环路。
在上述内容基础上，进一步地说明在例如图3所示的EVPN和VPLS共存双活网络中，针对所述场景一定义的BUM流量在广播域内的复制规则。为了更清楚地说明，首先对所述复制规则中涉及的概念予以澄清。本发明实施例所述的普通EVPN Peer指的是其本身属于EVPN类型的设备，但不属于网络中任一多归PE组中的成员的PE设备。例如，图3示出的PE25即为普通EVPN Peer，更特别地，PE25作为普通EVPN Peer还与VPLS侧的PE设备通过PW直连。此外，在EVPN和VPLS共存双活网络中，为了避免从EVPN侧向VPLS侧发送流量时，由于多归PW而导致的PE跳变，还需要针对跨网络的多归PW设置DF PW和BDF PW以加以区分。对于多归入同一PE设备的所有跨网络PW设置相同的ESI值，并且选举或设置其中一个跨网络PW作为该ESI值下的DF PW，其余跨网络PW则作为该ESI值下的BDF PW。作为一个具体示例，图3中EVPN侧的PE21和PE22均以跨网络PW形式与VPLS侧的PE23连接，即PE21和PE22通过跨网络的双归PW与PE23分别连接。此时，为连接PE21和PE23、以及PE22和PE23的PW标记相同的ESI值，即ESI1。并且通过选举或设置将连接所述PE21和PE23的跨网络PW标记为ESI1 DF PW，而将连接PE22和PE23的跨网络PW标记为ESI1 BDF PW。具体标记的方式例如可以通过设置新增的PW字段实现。类似的，对于PE21和PE22通过跨网络的双归PW与PE24分别连接的情况，将连接PE22和PE24的跨网络PW标记为ESI2 DF PW，而将连接PE21和PE24的跨网络PW标记为ESI2 BDF PW。需要说明的是，以上有关普通EVPN Peer、DF PW和BDF PW的解释也适用于本申请的其他实施例。
由此，针对所述场景一定义的BUM流量，EVPN侧和VPLS侧之间的复制转发规则具体如下：
R505由AC口进入的流量可以向跨网络DF PW复制；
R510由AC口进入的流量不向跨网络BDF PW复制；
R515由普通EVPN Peer进入的流量不向跨网络PW复制；
R520由多归PE进入的流量向跨网络DF PW复制；
R525跨网络PW接收到的流量只向AC口复制。
基于上述复制规则R505-R525，仍以图3示出的网络结构为例，分析在上述结构下对于BUM流量的复制转发情形，具体如图5a-5d所示。
图5a示出了从EVPN侧CE11发送的BUM1流量先由PE21接收时的复制转发过程。
在EVPN侧，CE11发出的BUM1流量被PE21接收后，PE21按照EVPN对于BUM1流量复制转发的一般性规则，将BUM1流量向PE21上用于接入CE14的AC口复制，但不会向PE21上与BUM1流量来源方的CE11对应的AC口复制，并且PE21还会将BUM1流量复制给其所有的EVPN Peer，即PE22和PE25。
而BUM1流量在PE21向PE23或PE24转发时，BUM1流量将由EVPN侧发往VPLS侧。此时，由于BUM1流量是由PE21上与CE11相连的AC口进入PE21的流量，因此需要适用上述复制规则R505和R510，即PE21向标记为DF PW的跨网络PW复制BUM1流量以发送至所述PE23，而PE21发现其与PE24之间的跨网络PW被标记为BDF PW，因此不向所述标记为BDF PW的跨网络PW复制BUM1流量，从而PE24不会接收到由PE21发送来的CE11的BUM1流量。
PE22在接收到PE21复制的BUM1流量后，基于EVPN的一般性规则，在EVPN侧 内将BUM1流量发送给PE22上用于接入CE16的AC口。并且，PE22发现BUM1流量中携带的ESI Label与其本地保存的ESI值相同，即BUM1流量来自于与其存在CE11双归关系的PE21，而PE22在CE11双归设备中被标记为BDF。此时，PE22基于EVPN水平分割原则，不再向CE11转发BUM1流量。同时，仍然按照EVPN的一般性规则，所述PE22也不会再向其他EVPN Peer复制BUM1流量，从而避免造成环路。当PE22向PE23或PE24转发BUM1流量时，PE22发现BUM1流量是从与其双归的PE21进入的流量，需要适用R520复制规则，由此PE22向标记为DF PW的跨网络PW复制BUM1流量，从而转发至PE24。但PE22不向标记为BDF PW的跨网络PW复制BUM1流量，从而PE23不会接收到由PE22发送来的CE11的BUM1流量。并且，PE23在接收到PE21通过跨网络DF PW复制的BUM1流量后，根据VPLS的一般性规则，仅向用于连接CE12的AC口转发BUM1流量，而不再向其他PW复制。与PE23的操作类似，PE24在接收到PE22通过跨网络DF PW复制的BUM1流量后，仅向用于连接CE12的AC口转发BUM1流量。
对于PE25而言，其在接收到PE21复制的BUM1流量后，按照EVPN的一般性规则，在EVPN侧内将BUM1流量发送给用于接入CE15的AC口，而在VPLS侧则按照VPLS的一般性规则，无需再向通过普通PW连接的PE23和PE24转发BUM1流量。由此，对于VPLS侧的CE设备CE12和CE13而言，从CE11发送的BUM1流量将从CE11-PE21-PE23这条转发路径发送至CE12，而CE13则经由CE11-PE21-PE22-PE24这条转发路径接收到CE11的BUM1流量，由此保证BUM1流量在PE23仅经过唯一的链路分别发送至CE12或CE13，使得流量从EVPN侧发往VPLS侧的CE设备时不会发生跳变。同时，EVPN侧的CE设备CE14、CE15和CE16也可以基于EVPN的一般性规则接收到CE11发出的BUM1流量，最终保证业务的正常运行。
由于CE11为双归模式，在某些情况下，例如CE11可以通过哈希算法或其他算法等随机决定是向PE21还是PE22发送BUM流量。在这种情况下，具体的复制转发过程可参见图5b。当CE11向PE22发送BUM2流量时，PE22接收到从CE11的AC口发送的BUM2流量，向VPLS侧复制流量遵循规则R505和R510，即经由DF PW向PE24复制，但不会向通过BDF PW与其连接的PE23复制。PE21在接收到PE22向其复制的BUM2流量后，其向VPLS侧复制流量时遵循规则R520。而PE25在接收到PE22向其复制的BUM2流量后，由于其属于普通EVPN Peer，按照EVPN的一般性规则，仅向PE25上用于连接CE15的AC口复制流量。PE23在接收到PE21发送的BUM2流量后，向PE23上用于连接CE12的AC口复制BUM2流量。与PE23的操作类似，PE24在接收到PE22发送的BUM2流量后，向PE24上用于连接CE13的AC口复制BUM2流量。由于转发过程与前述由PE21先接收BUM2流量的过程类似，故在此不再赘述。最终VPLS侧的CE12经由CE11-PE22-PE21-PE23这条转发路径接收到BUM2流量，而CE13则经由CE11-PE22-PE24接收到BUM2流量。
EVPN侧PE25在接收到CE15发送的BUM3流量时，整个网络的流量复制转发过程如图5c所示。由于PE25是普通EVPN Peer，因此应当适用EVPN的一般性规则，此时PE25将BUM3流量复制至EVPN Peer PE21和PE22，以及经由PW连接的PE23和PE24。所述PE21在接收到PE25复制的流量后，按照复制规则R515，即由普通EVPN Peer PE25进入的BUM3流量，仅向与其连接的CE11和CE14的AC复制，而不会经由任何跨网络PW，即与PE23连接的DF PW和BDF PW，以及与PE24连接的DF PW和BDF PW复制流量。 与PE21的操作类似，PE22在接收到PE25发送的BUM3流量时，也仅会向连接CE16的AC口复制。这样，可以保证PE23和PE24只会从PE25接收到BUM3流量，而不会从PE21或PE22接收到BUM3流量，由此保证PE23和PE24不会发生跳变。PE23和PE24在接收到BUM3流量后，按照规则R525，即从跨网络PW接收到的BUM3流量仅向AC口复制，因此各自向与其连接的CE12或CE13的AC口复制BUM3流量，而不会再向任何一个跨网络PW复制流量。
图5d示出的是从VPLS侧CE12发出的BUM4流量的复制转发过程。从CE12发出的BUM4流量到达PE23后向所有PW复制，此时PE21、PE22、PE24和PE25均收到BUM4流量。PE21在通过跨网络PW接收到BUM4流量后，按照规则R525向与其连接的CE14的AC口复制流量，并且由于其与CE11的连接被标记为DF，故也向CE11的AC口复制流量。而PE22在通过跨网络PW接收到BUM4流量后，按照规则R525向CE16的AC口复制流量，但由于其与CE11的连接被标记为BDF，结合EVPN的一般性规则，不再向CE11复制BUM4流量，以避免生成环路。PE25在接收到PE23复制的BUM4流量后，按照EVPN一般性的规则，在EVPN侧只向CE15复制流量，而在VPLS侧根据VPLS普通PW的一般性规则，即采用Full-mesh组网模式，PE25不会再向其他PW复制流量。同为VPLS侧的PE24设备在接收到PE23转发的BUM4流量后，直接将BUM4流量复制至CE13的AC口。而根据VPLS普通PW的一般性规则，PE24不会再向与其连接的PW发送BUM4流量，以防止形成环路。
场景二 PW为普通模式PW，转发流量为单播流量。
在EVPN和VPLS共存双活网络中，针对所述场景二定义单播流量基于MAC地址学习规则确定EVPN侧和VPLS侧之间的转发路径，所述MAC地址学习规则如下：
R605多归PE从DF PW学习MAC；
R610多归PE不从BDF PW学习MAC；
R615多归PE从DF PW学习MAC后，同步到EVPN Peer；增加跨网络PW标记；
R620 EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE地址；否则丢弃该MAC。
基于上述复制转发规则，仍以图3示出的网络结构为例，分析在相应结构下对于单播流量的转发情形。
按照规则R605和R610，PE21作为双归PE设备，仅PE21经由ESI1 DF PW从PE23学习到MAC1，但不会从ESI2 BDF PW学习到PE24的MAC2。与PE21的操作类似，PE22经由ESI2 DF PW从PE24学习到MAC2，但不会从ESI1 BDF PW学习到PE23的MAC1。按照规则R615双归PE21在学习到PE23的MAC1后，分别发送携带MAC1的第一报文至EVPN Peer PE22和PE25，从而将MAC1同步到EVPN Peer PE22和PE25。所述第一报文携带ESI1标签，并且PE21标记MAC1为经由跨网络PW获得。与PE21学习到MAC1后的操作类似，MAC2也通过PE22发送的第二报文同步到EVPN Peer PE21和PE25。所述第二报文携带ESI2标签，并且PE22标记MAC2为经由跨网络PW获得。可选地，所述标记的具体方式，例如可以是在携带MAC的报文中设置标志位，或者发送通知消息告知，或者其他任何可行的方式，只要能够使得接收方知晓其接收的MAC是经由跨网络PW获得的即可。
按照规则R620，EVPN Peer PE22学习到MAC1并得知MAC1经由跨网络PW获得， 此时将携带MAC1的第一报文中的ESI标签值与其本地存储的ESI值比较，发现存在相同的ESI标签值，即ESI1。PE22将自身的MAC指向PE21，即所述第一报文的发送方。PE21学习到MAC2并得知MAC2经由跨网络PW获得，此时将携带MAC2的第二报文中的ESI标签值与其本地存储的ESI值比较，发现存在相同的ESI2标签。PE21将自身的MAC指向PE22，即所述第二报文的发送方。同样依据规则R620，PE25在学习到MAC1或MAC2地址后，得知MAC1和MAC2为经由跨网络PW获得，于是检查本地存储的ESI值，但并没有匹配上所述第一报文携带的ESI1或第二报文携带的ESI2，因此丢弃MAC1和MAC2。
在上述学习MAC地址的基础上，单播流量的具体转发过程如图6所示。CE11双归至PE21和PE22，当CE11发送至CE12的第一单播流量先被转发至PE21时，PE21查询其第一MAC转发表并直接经过跨网络ESI1 DF PW向PE23转发，PE23接收到所述第一单播流量后，发送至CE12。而当CE11发送至CE12的第二单播流量先被转发至PE22时，PE22查询其第二MAC转发表，发现发送至CE12的MAC指向PE21，因此将所述第二单播流量发送至PE21，然后由PE21再查询所述第一MAC转发表，之后经过跨网络ESI1 DF PW向PE23转发，并最终发送至CE12。CE11发送至CE13的单播流量转发过程与上述过程类似，这里不再赘述。反之，当CE12发送第三单播流量至CE11时，PE23查询其第三MAC转发表，仅发现指向PE21的转发路径。因此，所述第三单播流量仅能通过CE12-PE23-PE21的转发路径到达CE11。
在一种可能的设计中，还进一步包括以下规则：
R625 EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI值，则将该ESI值对应的BDF PW设置为备份路径。
仍以图6所示为例，根据上述规则R625，PE22在接收到EVPN Peer PE21发送的所述第一报文时，发现所述第一报文中携带的ESI标签值为ESI1，而PE22本地存储有该ESI值，则将其与PE23连接的ESI1 BDF PW设置为备份路径，此时PE22和PE23分别将对方的MAC地址加入第二MAC转发表或第三转发表，但标记为CE11和CE12之间转发单播流量的备用MAC地址。如此，当PE21因发生故障或其他原因等不可用时，CE11和CE12之间的单播流量可以通过PE22和PE23之间的备份路径正常转发。类似地，PE21也可以将其与PE24连接的ESI2 BDF PW设置为备份路径，当PE22不可用时，用于CE11和CE13之间单播流量的转发。由此提高网络通信的健壮性和安全性。
需要说明的是，图6示出的为PE21和PE22互为双归PE且均只具有双归角色的情形，而多归角色除了示例的双归情形外，在其他可能的设计中，可以有多于两个PE互为多归PE的情况，进一步地，网络中的一个或多个PE可以同时承担单归PE和多归PE的角色，并且对于多归PE的角色，甚至可以同时属于多个不同的多归PE组，图6示出的情形不构成对本发明实施例的唯一限定。并且，当一个PE同时属于多个不同的多归PE组时，所述PE本地存储的ESI值也为多个，此时可通过任何可行的查找或匹配算法，确定该PE所接收报文中携带的ESI标签值是否与本地存储的多个ESI值中的任一个相同。无论上述哪种具体情形，或一些未明示的可能情形的组合和变形，只要涉及EVPN和VPLS共存双活的网络结构，均可采用所述规则R605-R620实现单播流量的MAC地址学习和正常转发。
以上场景一和场景二中的全部PW均为普通模式，而在一些实际组网场景中，PW也可以采用PW冗余保护组(英文：PW Redundancy Group，PWRG)的形式。PW冗余保护 组是可以在VPLS场景下使用的一种PW保护机制，通过对同一组业务部署多个设备进行冗余保护，从而提高设备故障的切换效率，减少业务的损失。为了在PW冗余保护组模式下保持原有的VPLS转发行为，需要保证形成冗余备份的一组PW中只有一条处于工作状态，其他的均处于备用状态。PW冗余保护组通常包括两种模式，即主/从(英文：Master/Slave)模式和自主(英文：Independent)模式。在Master/Slave模式下，由本地确定PW的主备，并通过信令协议通告远端，远端PE可以感知主备状态，PW侧和AC侧的主备关系互不影响，可以实现PW侧和AC侧故障隔离。在Independent模式下，本地PW的主备状态由远端AC侧协商结果确定，远端通告主备状态到本地，AC侧故障发生的保护倒换会影响PW侧同时进行保护倒换，不能实现故障隔离。PW冗余保护组中处于工作状态的PW称为主用PW(英文：Primary PW)，设定为优先用于流量转发。其他处于备用状态的PW称为备用PW(英文：Secondary PW)，在主用PW正常工作时不用于流量转发，但可以配置为接收流量。主用PW和备用PW可以通过PW的转发优先级配置参数确定，其中，最高优先级的PW作为主用PW。在Master/Slave模式下，本地设备可以通过所述转发优先级配置参数确定主备PW。但在Independent模式下，本地的PW转发状态不由转发优先级配置参数决定，而是根据远端学习的转发状态确定。
在EVPN和VPLS共存双活网络中，EVPN侧的多归PE也可能以PW冗余保护组的形式与VPLS侧的PE相连接。仍以图3为例，PE21和PE22为双归PE，PE23分别连接PE21和PE22的两个PW构成PW冗余保护组PWRG1。类似地，PE24分别连接PE21和PE22的两个PW构成PW冗余保护组PWRG2。而此前提及，对于同一组内PW，正常工作状态下只有主用PW支持转发，而备用PW不用于转发流量。但是备用PW可以配置为接收流量，即同一组内的PW支持多收模式。当备用PW仅为一条时，主备PW即为支持双收模式。因此，仍以图3示出的网络结构作为示例，基于PWRG1和/或PWRG2是否支持双收，以及转发的流量类型为BUM流量还是单播流量，以下继续分为四个不同的场景予以描述。
场景三多归PE的PW构成PW冗余保护组且不支持双收，转发流量为BUM流量。
针对所述场景三定义的BUM流量，EVPN侧和VPLS侧之间的复制转发规则具体如下：
R705由AC口进入的流量可以向跨网络DF PW复制；
R710由AC口进入的流量不向跨网络BDF PW复制；
R715由普通EVPN Peer进入的流量不向跨网络PW复制；
R720由多归PE进入的流量向跨网络DF PW复制；
R725跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；
R730多归PE接收到携带ESI标签的流量后，只向AC口复制。
当BUM流量从EVPN侧向VPLS侧转发时，对于上述复制规则R705-R720，其适用场景和方式与前述规则R505-R520相同，BUM流量转发过程示例可参见图5a-5c，这里不再赘述。特别需要说明的是，不同于适用于跨网络普通PW转发的规则R510，由于对于不支持双收的PW冗余保护组而言，其自身机制可以保证备用PW在接收到PE发送的BUM流量后不会向AC口复制，由此已经可以避免BUM流量在本地发生跳变。因此，在一种可能的设计中，可以将规则R710删除，此时即使BDF PW接收到BUM流量，其也不会 再向与其连接的AC口复制。而在保留R710的情形下，则能够节约带宽和开销。
当BUM流量从VPLS侧向EVPN侧转发时，适用规则R725和R730。仍以图3示出的网络结构为例，从CE12发出的BUM5流量由PE23接收后，由于PE23以PW冗余保护组形式与双归PE21和PE22连接，此时按照VPLS冗余保护组的转发规则，BUM5流量只会经由ESI1 DF PW转发至PE21，而不再像图5d示出的以跨网络普通PW方式连接时，BUM5流量会同时向PE21和PE22复制转发。由此，PE22需要通过与其双归的PE21接收BUM5流量。根据规则R725，PE21在经由跨网络PW ESI1 DF PW接收到BUM5流量后，向与其连接的CE设备的AC口复制，并且根据EVPN的一般性规则，PE21为与CE11连接的DF设备，因此，BUM5流量可以从PE21向CE11和CE14复制。同时，根据规则R725，PE21还可以向与其双归的PE22复制，并且需要在BUM5流量中携带ESI1标签。根据规则R730，与PE21双归的PE22在接收到BUM5流量后，发现流量携带ESI1标签，于是仅向与其连接的CE设备的AC口复制。但根据EVPN的一般性规则，作为BDF的PE22不能再向CE11复制BUM5流量，因此，BUM5流量仅可以从PE22向CE16复制。以上BUM5流量从CE12发出的复制转发过程可参见图7。对于PE24与双归PE21和PE22以PW冗余保护组形式连接的情况，其BUM流量也采用类似的复制转发过程。
场景四多归PE的PW构成PW冗余保护组且不支持双收，转发流量为单播流量。
针对所述场景四定义的单播流量，基于MAC地址学习规则确定EVPN侧和VPLS侧之间的转发路径，所述MAC地址学习规则如下：
R805多归PE从DF PW学习MAC；
R810多归PE不从BDF PW学习MAC；
R815多归PE从DF PW学习MAC后，同步到EVPN Peer；增加跨网络PW标记；
R820 EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE地址；否则丢弃该MAC。
在此场景下，单播流量MAC地址学习过程及复制规则与R605-R620相同，单播流量转发过程示例可参见图6，这里不再赘述。同样地，在一种可能的设计中，该场景四还可以进一步包括规则R825 EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI值，则将该ESI值对应的BDF PW设置为备份路径。
场景五多归PE的PW构成PW冗余保护组且支持双收，转发流量为BUM流量。
针对所述场景五定义的BUM流量，EVPN侧和VPLS侧之间的复制转发规则具体如下：
R905由AC口进入的流量可以向跨网络DF PW复制；
R910由AC口进入的流量可以向跨网络BDF PW复制；
R915由普通EVPN Peer进入的流量不向跨网络PW复制；
R920由多归PE进入的流量不向跨网络DF PW复制；
R925跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；
R930多归PE接收到携带ESI标签的流量后，只向AC口复制。
仍以图3网络结构为示例，如果双归的PE21和PE22在与PE23连接时，其PW为冗余保护组模式并且支持双收。按照规则R905-R910，CE11发出的BUM流量，即从AC口进入的流量将向PE21和PE22复制，由于用于转发PE21复制的流量至PE23的ESI1 DF  PW，以及转发PE22复制的流量至PE23的ESI1 BDF PW构成支持双收的PW冗余保护组，按照PW冗余保护组自身的双收机制，可以保证PE23设备不会发生跳变。进一步地，由于BUM流量已经按照双收机制由PE21和PE22向PE23复制，因此设置规则R920，PE21或PE22不再转发由彼此复制过来的BUM流量，由此避免产生环路。至于规则R915、R925-R930与场景三中定义的规则R715、R725-R730的适用方式相同，在此不再赘述。如果PE21和PE22分别与PE24连接的PW也构成PW冗余保护组并且支持双收，则发送至PE24的BUM流量转发过程与PE23相同。
场景六多归PE的PW构成PW冗余保护组且支持双收，转发流量为单播流量。
针对上述场景六，单播流量基于MAC地址学习规则确定EVPN侧和VPLS侧之间的转发路径，所述MAC地址学习规则如下：
R1005多归PE从DF PW学习MAC；
R1010多归PE从BDF PW学习MAC；
R1015多归PE从DF PW学习MAC后，同步到EVPN Peer；增加跨网络PW标记；
R1020 EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE地址；否则丢弃该MAC。
仍以图3为例，在双归PE21和PE22与PE23之间的连接为PW冗余保护组且支持双收的情形下，允许PE23从PE21和PE22接收单播流量，因此参见规则R1005，PE21经由ESI DF PW学习到PE23的MAC地址。而参见规则R1010，PE22也可以经由ESI BDF PW学习到PE23的MAC地址。本场景六下的其余复制规则的适用可参见前述场景二中的相应描述，在此不再赘述。同样地，在一种可能的设计中，该场景六还可以进一步包括规则R1025EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI值，则将该ESI值对应的BDF PW设置为备份路径，从而提高网络传输的可靠性和健壮性。
需要特别说明的是，在实际情形下，连接EVPN侧多归PE与VPLS侧PE的PW模式可以相同，也可以不同。例如，图3中至少包括(1)双归PE21和PE22分别与PE23连接的两个PW；(2)双归PE21和PE22分别与PE24连接的两个PW。上述两组PW(1)和(2)的PW模式可以是从普通PW、PW冗余保护组且不支持双收、以及PW冗余保护组且支持双收中任意选择的相同或不同的组合。在确定具体组合方式后，第(1)组和第(2)组PW分别按照其确定后的PW模式类型和流量类型而适用相应的复制规则即可。为了更清楚地说明，这里对一种可能会产生混淆的情景的复制规则予以进一步阐述，所述情景如图8所示。双归PE21和PE22与PE23的PW连接为冗余保护组但不支持双收模式，双归PE21和PE22与PE24的PW连接为冗余保护组且支持双收模式，上述两组冗余保护组均将PE21设备的PW连接设置为DF PW。此时，如果转发的流量为BUM6流量，则对于从PE22发出的BUM6流量在复制至PE21后，由于PE21与PE23之间的ESI1 DF PW为不支持双收模式，则参见规则R720，BUM6流量在双归PE21向ESI1 DF PW复制。而由于PE21与PE24之间的ESI2 DF PW为支持双收模式，则参见规则R920，BUM6流量在双归PE21并不向ESI2 DF PW复制。
由于在复制和转发单播流量时，需要根据PW的不同类型确定不同的MAC学习策略和复制转发规则，因此有必要在学习MAC时为相应的MAC地址标注其来源PW的跨网络PW类型，包括普通PW、PW冗余保护组且不支持双收、以及PW冗余保护组且支持双收三种类型，并且对于组成同一PW冗余保护组的PW需要设置相同的ESI标签。为此， 可以考虑以任何可实施的方式为MAC地址进行PW标记。可选地，例如考虑(1)新增MAC扩展团体属性，通过字段Flags标记并区分PW的三种类型，如图9a所示；或者(2)复用已有的MAC迁移属性，使用字段Flags的空余位标记并区分PW的三种类型，如图9b所示。
以上，结合图3-图8详细说明了根据本申请实施例提供的流量复制转发方法和复制转发规则。接下来，结合图10说明根据本申请实施例提供的用于流量转发的PE设备。
图10是根据本申请实施例提供的一种网络设备500的示意图。该网络设备500例如可以是图3中EVPN侧的PE设备PE21或PE22，可以用于执行图4所示的方法。该网络设备500包括：存储器501、处理器502和网络接口503。网络接口503，用于接收其他PE设备转发的流量，或将所述流量按照转发规则发送至其他PE设备，例如所述网络接口503可以是以太网网口。
存储器501，用于存储计算机可读指令。
处理器502，用于调用所述计算机可读指令，以执行：所述网络设备与多个其他网络设备运行EVPN，其中所述网络设备作为PE设备与所述EVPN中的至少一个PE形成针对一个CE设备或终端设备的多归结构；
与处于VPLS中的至少一个PE通过跨网络伪线PW相连接；
通过网络接口503接收数据流量；
根据所述数据流量与以下条件的匹配结果，通过网络接口503对所述数据流量进行转发，其中，所述条件包括：(1)由其他PE设备经由所述网络设备的跨网络PW发送，(2)需要由所述网络设备转发至经由跨网络PW连接的PE设备，和/或(3)包括跨网络PW的标记。
以图3中的网络设备PE21接收PE22发送的单播流量，并转发所述单播流量至CE12设备为例。网络设备PE21与其他网络设备PE22和PE25运行EVPN，其中与PE22形成针对CE11的双归结构，并且与处于VPLS中的PE23和PE24分别通过跨网络PW相连接，所述跨网络PW例如可以是普通PW模式。在一种可能的情形下，PE21接收由PE22发送的单播流量。在学习MAC路由时，PE22经由普通PW模式的跨网络PW ESI2 DF PW学习到PE24的MAC路由，并在学习到PE24的MAC路由后，为该MAC路由增加跨网络PW标记。因此，PE21在接收由PE22发送的单播流量时，会发现所述单播流量中包括跨网络PW标记，即符合上述条件(3)，此时PE21按照跨网络PW确定的MAC学习和转发规则向PE23转发所述单播流量。
在其他可能的设计中，用于接收和转发数据流量的网络接口可以为多个。当网络接口有多个时，用于接收和转发数据流量的网络接口可以相同，也可以不同。
本申请实施例还提供了一种流量转发系统600，例如可以是图3示出的网络系统结构。所述系统600包括多个第一PE设备，所述多个第一PE设备为EVPN设备，并且所述多个第一PE设备形成针对一个CE设备或终端设备的多归结构。例如，图3中的EVPN设备PE21和PE22即形成针对CE11设备的双归结构。
所述多归结构中的每个第一PE设备与相同的至少一个第二PE设备通过跨网络PW相连接，所述第二PE设备为VPLS设备。例如图3中的双归结构PE21和PE22分别通过跨网络PW与VPLS设备PE23和PE24两两相连。
所述第一PE设备接收数据流量；
所述第一PE设备根据所述数据流量与以下条件的匹配结果，对所述数据流量进行转发，其中，所述条件包括：
(1)由其他PE设备经由所述网络设备的跨网络PW发送，(2)需要由所述网络设备转发至经由跨网络PW连接的PE设备，和/或(3)包括跨网络PW的标记。
以图3中VPLS侧的CE设备CE12向EVPN侧的CE设备CE11发送BUM流量为例。CE12发送所述BUM流量后，由VPLS设备PE23接收。VPLS设备PE23基于VPLS的一般性转发规则，经由与其连接的PW向PE21转发所述BUM流量，而所述PW具体为跨网络PW模式，即此时作为第一PE设备的PE21发现PE23经由PE21的跨网络PW发送所述BUM流量，符合上述条件(3)，因此PE21按照跨网络PW确定的规则继续转发所述BUM流量。
本申请实施例还提供了另一种流量转发系统700，如图11所示。系统700包括：
第一连接单元705，用于第一网络设备与网络中的多个其他网络设备运行以太网虚拟私有网EVPN，其中所述第一网络设备作为运营商边缘PE设备与所述EVPN中的至少一个PE形成针对一个客户边缘CE设备或终端设备的多归结构；
第二连接单元710，用于第一网络设备与处于虚拟专用局域网VPLS中的至少一个PE通过跨网络伪线PW相连接；
接收单元715，用于第一网络设备接收数据流量；
匹配单元720，用于第一网络设备根据所述数据流量与以下条件的匹配结果，对所述数据流量进行转发，其中，所述条件包括：
(1)由其他PE设备经由所述第一网络设备的跨网络PW发送，(2)需要由所述第一网络设备转发至经由跨网络PW连接的PE设备，和/或(3)包括跨网络PW的标记。
所述网络设备500、流量转发系统600或流量转发系统700在满足上述条件时具体适用的跨网络PW的复制规则和流量转发过程可参见上述方法实施例中的场景一至六，这里不再赘述。
本申请实施例还提供了一种计算机可读存储介质或者计算机程序产品，用于存储计算机程序，该计算机程序用于执行上述的流量转发方法400。
应理解，在本申请实施例中，该处理器501实现的功能可以是硬件的集成逻辑电路或软件形式的指令完成，具体例如中央处理单元CPU，还可以是其他通用处理器、数字信号处理器DSP、专用集成电路ASIC、现成可编程门阵列FPGA或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。
应理解，在本申请实施例中，该网络接口501实现的流量收发功能可以由一个独立的单元完成，也可以进一步包括例如接收子单元和发送子单元，分别用于实现流量的接收和转发等，这里不作具体限定。
应理解，在本申请的各种实施例中，各过程的序号大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请实施例的实施过程构成任何限定。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的模块及方法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可 以对每个特定的应用来使用不同方法来实现所描述的功能。
在上述实施例中，可以全部或部分地通过软件、硬件、固件或者其任意组合来实现。当使用软件实现时，可以全部或部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令。在计算机上加载和执行所述计算机程序指令时，全部或部分地产生按照本申请实施例所述的流程或功能。所述计算机可以是通用计算机、专用计算机、计算机网络、或者其他可编程装置。所述计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质传输，例如，所述计算机指令可以从一个网站站点、计算机、服务器或数据中心通过有线(例如同轴电缆、光纤、数字用户线(DSL))或无线(例如红外、无线、微波等)方式向另一个网站站点、计算机、服务器或数据中心进行传输。所述计算机可读存储介质可以是计算机能够存取的任何可用介质或者是包含一个或多个可用介质集成的服务器、数据中心等数据存储设备。所述可用介质可以是磁性介质，(例如，软盘、硬盘、磁带)、光介质(例如，DVD)、或者半导体介质(例如固态硬盘Solid State Disk(SSD))等。本说明书的各个部分均采用递进的方式进行描述，各个实施例之间相同相似的部分互相参见即可，每个实施例重点介绍的都是与其他实施例不同之处。尤其，对于装置和系统实施例而言，由于其基本相似于方法实施例，所以描述的比较简单，相关之处参见方法实施例部分的说明即可。
最后，需要说明的是：以上所述仅为本申请技术方案的较佳实施例而已，并非用于限定本申请的保护范围。

Claims (20)

  1. 一种流量转发方法，所述方法包括：
    第一网络设备与网络中的多个其他网络设备运行以太网虚拟私有网EVPN，其中所述第一网络设备作为运营商边缘PE设备与所述EVPN中的至少一个PE形成针对一个客户边缘CE设备或终端设备的多归结构；
    与处于虚拟专用局域网VPLS中的至少一个PE通过跨网络伪线PW相连接；
    接收数据流量；
    根据所述数据流量与以下条件的匹配结果，对所述数据流量进行转发，其中，所述条件包括：
    (1)由其他PE设备经由所述第一网络设备的跨网络PW发送，(2)需要由所述第一网络设备转发至经由跨网络PW连接的PE设备，和/或(3)包括跨网络PW的标记。
  2. 根据权利要求1所述的方法，其特征在于，连接所述第一网络设备的跨网络PW的模式为普通PW、PW保护组且不支持双收、或PW保护组且支持双收的模式。
  3. 根据权利要求2所述的方法，其特征在于，对于连接所述一组多归结构PE的多个跨网络PW，其中一个跨网络PW作为指定转发DF PW，其余的跨网络PW作为备用指定转发BDF PW。
  4. 根据权利要求3所述的方法，其特征在于，当跨网络PW的模式为普通PW，并且转发流量为BUM流量时，所述第一网络设备基于以下规则转发所述BUM流量：
    由AC口进入的流量可以向跨网络DF PW复制；
    由AC口进入的流量不向跨网络BDF PW复制；
    由普通EVPN对等体EVPN Peer进入的流量不向跨网络PW复制；
    由多归PE进入的流量向跨网络DF PW复制；
    跨网络PW接收到的流量只向AC口复制；
    其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
  5. 根据权利要求3所述的方法，其特征在于，当跨网络PW模式为普通PW，并且转发流量为单播流量时，所述第一网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：
    多归PE从DF PW学习MAC；
    多归PE不从BDF PW学习MAC；
    多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；
    EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
  6. 根据权利要求3所述的方法，其特征在于，当跨网络PW模式为PW保护组且不支持双收，并且转发流量为BUM流量时，所述第一网络设备基于以下规则转发所述BUM流量：
    由AC口进入的流量可以向跨网络DF PW复制；
    由普通EVPN Peer进入的流量不向跨网络PW复制；
    由多归PE进入的流量向跨网络DF PW复制；
    跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；
    多归PE接收到携带ESI标签的流量后，只向AC口复制；
    其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
  7. 根据权利要求3所述的方法，其特征在于，当跨网络PW模式为PW保护组且不支持双收，并且转发流量为单播流量时，所述第一网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：
    多归PE从DF PW学习MAC；
    多归PE不从BDF PW学习MAC；
    多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；
    EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
  8. 根据权利要求3所述的方法，其特征在于，当跨网络PW模式为PW保护组且支持双收，并且转发流量为BUM流量时，所述第一网络设备基于以下规则转发所述BUM流量：
    由AC口进入的流量可以向跨网络DF PW复制；
    由AC口进入的流量可以向跨网络BDF PW复制；
    由普通EVPN Peer进入的流量不向跨网络PW复制；
    由多归PE进入的流量不向跨网络DF PW复制；
    跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；
    多归PE接收到携带ESI标签的流量后，只向AC口复制；
    其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
  9. 根据权利要求3所述的方法，其特征在于，当跨网络PW模式为PW保护组且支持双收，并且转发流量为单播流量时，所述第一网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：
    多归PE从DF PW学习MAC；
    多归PE从BDF PW学习MAC；
    多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；
    EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
  10. 一种网络设备，包括：
    存储器，用于存储计算机可读指令；以及
    处理器，用于调用所述计算机可读指令，以执行：
    所述网络设备与多个其他网络设备运行以太网虚拟私有网EVPN，其中所述网络设备作为运营商边缘PE设备与所述EVPN中的至少一个PE形成针对一个客户边缘CE设备或终端设备的多归结构；
    与处于虚拟专用局域网VPLS中的至少一个PE通过跨网络伪线PW相连接；
    接收数据流量；
    根据所述数据流量与以下条件的匹配结果，对所述数据流量进行转发，其中，所述条 件包括：
    (1)由其他PE设备经由所述网络设备的跨网络PW发送，(2)需要由所述网络设备转发至经由跨网络PW连接的PE设备，和/或(3)包括跨网络PW的标记。
  11. 根据权利要求10所述的方法，其特征在于，连接所述网络设备的跨网络PW的模式为普通PW、PW保护组且不支持双收、或PW保护组且支持双收的模式。
  12. 根据权利要求11所述的方法，其特征在于，对于连接所述一组多归结构PE的多个跨网络PW，其中一个跨网络PW作为指定转发DF PW，其余的跨网络PW作为备用指定转发BDF PW。
  13. 根据权利要求12所述的方法，其特征在于，当跨网络PW的模式为普通PW，并且转发流量为BUM流量时，所述网络设备基于以下规则转发所述BUM流量：
    由AC口进入的流量可以向跨网络DF PW复制；
    由AC口进入的流量不向跨网络BDF PW复制；
    由普通EVPN对等体EVPN Peer进入的流量不向跨网络PW复制；
    由多归PE进入的流量向跨网络DF PW复制；
    跨网络PW接收到的流量只向AC口复制；
    其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
  14. 根据权利要求12所述的方法，其特征在于，当跨网络PW模式为普通PW，并且转发流量为单播流量时，所述网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：
    多归PE从DF PW学习MAC；
    多归PE不从BDF PW学习MAC；
    多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；
    EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
  15. 根据权利要求12所述的方法，其特征在于，当跨网络PW模式为PW保护组且不支持双收，并且转发流量为BUM流量时，所述网络设备基于以下规则转发所述BUM流量：
    由AC口进入的流量可以向跨网络DF PW复制；
    由普通EVPN Peer进入的流量不向跨网络PW复制；
    由多归PE进入的流量向跨网络DF PW复制；
    跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；
    多归PE接收到携带ESI标签的流量后，只向AC口复制；
    其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
  16. 根据权利要求12所述的方法，其特征在于，当跨网络PW模式为PW保护组且不支持双收，并且转发流量为单播流量时，所述网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：
    多归PE从DF PW学习MAC；
    多归PE不从BDF PW学习MAC；
    多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；
    EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
  17. 根据权利要求12所述的方法，其特征在于，当跨网络PW模式为PW保护组且支持双收，并且转发流量为BUM流量时，所述网络设备基于以下规则转发所述BUM流量：
    由AC口进入的流量可以向跨网络DF PW复制；
    由AC口进入的流量可以向跨网络BDF PW复制；
    由普通EVPN Peer进入的流量不向跨网络PW复制；
    由多归PE进入的流量不向跨网络DF PW复制；
    跨网络PW接收到的流量向AC口和多归PE复制，向多归PE复制时携带ESI标签；
    多归PE接收到携带ESI标签的流量后，只向AC口复制；
    其中，所述普通EVPN Peer与所述多个PE设备中的至少一个构成EVPN Peer，但其本身不属于多归PE。
  18. 根据权利要求12所述的方法，其特征在于，当跨网络PW模式为PW保护组且支持双收，并且转发流量为单播流量时，所述网络设备基于MAC地址学习确定转发路径，所述MAC地址学习规则如下：
    多归PE从DF PW学习MAC；
    多归PE从BDF PW学习MAC；
    多归PE从DF PW学习MAC后，同步到EVPN Peer，增加跨网络PW标记；
    EVPN Peer发现跨网络PW标记的MAC后，如发现本地具有携带该MAC的报文中的ESI标签值，则将自身MAC指向发送该报文的PE设备地址，否则丢弃该MAC。
  19. 一种流量转发系统，所述系统包括：
    第一连接单元，用于第一网络设备与网络中的多个其他网络设备运行以太网虚拟私有网EVPN，其中所述第一网络设备作为运营商边缘PE设备与所述EVPN中的至少一个PE形成针对一个客户边缘CE设备或终端设备的多归结构；
    第二连接单元，用于第一网络设备与处于虚拟专用局域网VPLS中的至少一个PE通过跨网络伪线PW相连接；
    接收单元，用于第一网络设备接收数据流量；
    匹配单元，用于第一网络设备根据所述数据流量与以下条件的匹配结果，对所述数据流量进行转发，其中，所述条件包括：
    (1)由其他PE设备经由所述第一网络设备的跨网络PW发送，(2)需要由所述第一网络设备转发至经由跨网络PW连接的PE设备，和/或(3)包括跨网络PW的标记。
  20. 一种流量转发系统，所述系统包括：
    多个第一运营商边缘PE设备，所述多个第一PE设备为以太网虚拟私有网EVPN设备，并且所述多个第一PE设备形成针对一个客户边缘CE设备或终端设备的多归结构；
    所述多归结构中的每个第一PE设备均与相同的至少一个第二PE设备通过跨网络伪线PW相连接，所述第二PE设备为虚拟专用局域网VPLS设备；
    所述第一PE设备接收数据流量；
    所述第一PE设备根据所述数据流量与以下条件的匹配结果，对所述数据流量进行转发，其中，所述条件包括：
    (1)由其他PE设备经由所述网络设备的跨网络PW发送，(2)需要由所述网络设备转发至经由跨网络PW连接的PE设备，和/或(3)包括跨网络PW的标记。
PCT/CN2020/092705 2019-08-22 2020-05-27 Evpn和vpls共存双活的方法、设备及系统 WO2021031648A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP20855159.8A EP4016932A4 (en) 2019-08-22 2020-05-27 METHOD, APPARATUS AND SYSTEM FOR COEXISTING EVPN AND VPLS
US17/675,218 US20220174006A1 (en) 2019-08-22 2022-02-18 Method for EVPN and VPLS Active-Active Integration, Device, and System

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201910779880.X 2019-08-22
CN201910779880.XA CN112422307B (zh) 2019-08-22 2019-08-22 Evpn和vpls共存双活的方法、设备及系统

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US17/675,218 Continuation US20220174006A1 (en) 2019-08-22 2022-02-18 Method for EVPN and VPLS Active-Active Integration, Device, and System

Publications (1)

Publication Number Publication Date
WO2021031648A1 true WO2021031648A1 (zh) 2021-02-25

Family

ID=74659960

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/092705 WO2021031648A1 (zh) 2019-08-22 2020-05-27 Evpn和vpls共存双活的方法、设备及系统

Country Status (4)

Country Link
US (1) US20220174006A1 (zh)
EP (1) EP4016932A4 (zh)
CN (1) CN112422307B (zh)
WO (1) WO2021031648A1 (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113726633A (zh) * 2021-08-12 2021-11-30 中国联合网络通信集团有限公司 转发方法和转发装置
CN113992573A (zh) * 2021-10-26 2022-01-28 新华三信息安全技术有限公司 一种转发bum流量的方法、装置、pe设备及存储介质

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112311643B (zh) * 2019-07-24 2023-04-18 深圳市中兴微电子技术有限公司 一种evpn报文转发方法、系统、存储介质和终端
CN114760243A (zh) * 2020-12-25 2022-07-15 华为技术有限公司 报文传输方法、设备及系统
CN113992567B (zh) * 2021-10-26 2023-03-21 新华三信息安全技术有限公司 一种报文转发方法及装置
CN115174438B (zh) * 2022-07-05 2023-09-22 杭州云合智网技术有限公司 Vpws双活双归属的业务连通性的识别方法
CN115426296B (zh) * 2022-08-31 2023-10-13 杭州云合智网技术有限公司 在evpn vpws双归属双活下的连通确认方法、装置、设备及介质
CN115567443B (zh) * 2022-09-23 2024-06-04 中国联合网络通信集团有限公司 业务数据的传输方法、装置、网关设备及存储介质

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105991432A (zh) * 2015-03-18 2016-10-05 丛林网络公司 提供商边缘路由器及方法
CN106878253A (zh) * 2015-09-30 2017-06-20 丛林网络公司 Mac（l2）层认证、安全性和策略控制
CN108156067A (zh) * 2018-01-07 2018-06-12 何顺民 一种实现基于以太网虚拟专用网络的方法和系统
US20190109730A1 (en) * 2017-10-06 2019-04-11 At&T Intellectual Property I, L.P. Virtual private network interworking
CN109951371A (zh) * 2019-03-29 2019-06-28 新华三技术有限公司 数据转发方法及装置
CN110113260A (zh) * 2019-04-28 2019-08-09 新华三技术有限公司 一种转发表更新方法及装置

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101371525A (zh) * 2005-10-05 2009-02-18 北方电讯网络有限公司 提供商骨干桥接-提供商骨干传输网际互连
CN102170710B (zh) * 2010-02-26 2016-01-20 中兴通讯股份有限公司 一种在标签交换路径中实现叶子节点发现的方法及系统
US8416775B2 (en) * 2010-05-19 2013-04-09 Juniper Networks, Inc. Systems and methods for equal-cost multi-path virtual private LAN service
US8948169B2 (en) * 2011-12-07 2015-02-03 Cisco Technology, Inc. Mechanism for E-VPN interoperability with VPLS
CN103731288B (zh) * 2012-10-16 2017-04-12 杭州华三通信技术有限公司 报文转发方法及设备
CN103475557B (zh) * 2013-09-05 2017-02-08 华为技术有限公司 隧道建立的方法及路由器
US9794168B2 (en) * 2015-08-05 2017-10-17 Cisco Technology, Inc. Scalable continuity test for a group of communication paths
US10250552B1 (en) * 2016-04-27 2019-04-02 Cisco Technology, Inc. L3VPN service with single IGP/BGP session from a multi-homed CE with fast convergence using EVPN
US10666459B1 (en) * 2017-04-07 2020-05-26 Cisco Technology, Inc. System and method to facilitate interoperability between virtual private LAN service (VPLS) and ethernet virtual private network (EVPN) with all-active multi-homing
US10630509B2 (en) * 2018-03-30 2020-04-21 Juniper Networks, Inc. Aliasing behavior for traffic to multihomed sites in ethernet virtual private network (EVPN) networks
US10771383B2 (en) * 2018-06-26 2020-09-08 Juniper Networks, Inc. Coordinating pseudowire connection characteristics and multi-homed provider edge device capabilities
CN109995651B (zh) * 2019-03-28 2021-05-14 新华三技术有限公司 一种伪线建立方法及装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105991432A (zh) * 2015-03-18 2016-10-05 丛林网络公司 提供商边缘路由器及方法
CN106878253A (zh) * 2015-09-30 2017-06-20 丛林网络公司 Mac（l2）层认证、安全性和策略控制
US20190109730A1 (en) * 2017-10-06 2019-04-11 At&T Intellectual Property I, L.P. Virtual private network interworking
CN108156067A (zh) * 2018-01-07 2018-06-12 何顺民 一种实现基于以太网虚拟专用网络的方法和系统
CN109951371A (zh) * 2019-03-29 2019-06-28 新华三技术有限公司 数据转发方法及装置
CN110113260A (zh) * 2019-04-28 2019-08-09 新华三技术有限公司 一种转发表更新方法及装置

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113726633A (zh) * 2021-08-12 2021-11-30 中国联合网络通信集团有限公司 转发方法和转发装置
CN113992573A (zh) * 2021-10-26 2022-01-28 新华三信息安全技术有限公司 一种转发bum流量的方法、装置、pe设备及存储介质

Also Published As

Publication number Publication date
EP4016932A1 (en) 2022-06-22
CN112422307A (zh) 2021-02-26
US20220174006A1 (en) 2022-06-02
CN112422307B (zh) 2022-06-14
EP4016932A4 (en) 2022-10-26

Similar Documents

Publication Publication Date Title
WO2021031648A1 (zh) Evpn和vpls共存双活的方法、设备及系统
US10862783B2 (en) OAM mechanisms for EVPN active-active services
US9019814B1 (en) Fast failover in multi-homed ethernet virtual private networks
US9781032B1 (en) MPLS label usage in ethernet virtual private networks
US9832097B2 (en) Method and apparatus for MPLS label allocation for a BGP MAC-VPN
US9858163B2 (en) Dual adjacency between edge devices at a network site
JP5661929B2 (ja) マルチシャーシリンクアグリゲーションのためのシステムおよび方法
US11349749B2 (en) Node protection for bum traffic for multi-homed node failure
US11985002B2 (en) Protocol independent multicast (PIM) designated router (DR) election
US9660898B2 (en) Enhanced protocol independent multicast source registration over a reliable transport
CN105939257A (zh) Evpn单活动拓扑中的mac路由的更新
CN111935013B (zh) 流量转发控制方法及装置、流量转发方法及芯片、交换机
CN111064596B (zh) 对于用于多宿主节点故障的bum流量的节点保护
WO2012130034A1 (zh) 一种vpls快速重路由方法和设备
US20210328936A1 (en) Method for determining designated forwarder (df) of multicast flow, device, and system
WO2013139159A1 (zh) 在网络中转发报文的方法和运营商边缘设备
WO2022053007A1 (zh) 网络可达性验证方法及装置、计算机存储介质
US9548887B2 (en) Proactive creation of multicast state in an overlay transport network to achieve fast convergence on failover
WO2023035983A1 (zh) 指定转发者df选举的方法及设备
CN111565141B (zh) 数据传输方法、第一pe和第二pe
WO2020135888A1 (zh) 流量的传输方法及装置，物理拓扑结构
NIKOLAOS Overview and implementation of modern Data Center Interconnect technologies

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20855159

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2020855159

Country of ref document: EP

Effective date: 20220318