WO2012171378A1

WO2012171378A1 - Method and router for preventing flow interruption caused by failover from vpls to l3

Info

Publication number: WO2012171378A1
Application number: PCT/CN2012/072754
Authority: WO
Inventors: 倪中华; 郭剑
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-06-15
Filing date: 2012-03-21
Publication date: 2012-12-20
Also published as: CN102244609A; CN102244609B

Abstract

Disclosed in the present invention is a method for preventing flow interruption caused by failover from virtual private LAN service (VPLS) to network layer 3(L3). The method comprises the following steps: configuring a local preference value or path-length metric value of the border gateway protocol(BGP); configuring master-slave relationship of the virtual router redundancy protocol (VRRP); and when the master-slave relationship of the VRRP is formed, changing the local preference value or metric value of the BGP so that the path of route advertisement of the BGP is consistent with that of the master-slave relationship of the VRRP. The invention discloses a router. By the invention, reliability of equipment, links and networks is improved.

Description

Method and router for solving VPLS access L3 failover causing current interruption

The present invention relates to the field of IP communication technologies, and in particular to a method and a router for solving a VPLS (Virtual Private LAN Service) access L3 (network side) failover and causing a current interruption. Background technique

BGP (Border Gateway Protocol) is a routing protocol that dynamically exchanges routing information between autonomous systems. A classic definition of an autonomous system is a set of routers under the control of a management authority that uses IBGP (Insular Border Gateway Protocol) and common metrics to forward messages to other autonomous systems.

The value of the local preference and the metric are the two routing attributes of BGP. The characteristics of the local preference are: 1. The local preference value is in multiple paths to the same destination network. The greater the local preference value is. The default value is 2; the default value of the local preference value is 100; the attribute of the local preference value can be passed in the same autonomous system. The local priority is only passed in the entire AS (Autonomous System), and the local preference is set. The value of the router will notify the IBGP neighbors of the priority when leaving the AS from itself, thus achieving the effect of neighbor routing. 3. The metric (path length) value is exchanged between the autonomous systems. The autonomous system uses the attribute of the local preference value to influence its outbound selection, and the metric value to influence the outbound selection of another autonomous system. Similar to the metric value of other routing protocols, the smaller the metric value, the higher the priority.

VRRP (Virtual Router Redundancy Protocol) is a selection protocol that can be divided into VRRP routers and virtual routers, and can be divided into primary routers and standby routers. Where: VRRP router refers to the router running VRRP, which is physical Entity; Virtual router is created by VRRP and is a logical concept. A group of VRRP routers work together to form a virtual router. The virtual router appears externally as a logical router with a unique fixed IP address and MAC address. A router in the same VRRP group has two mutually exclusive roles: a primary router and a standby router. One VRRP group has only one router in the master role, that is, the primary router. One or more of them can be backed up. The role of the router, the ready router. The VRRP protocol uses the selection policy to select one of the router groups as the master. It is responsible for the corresponding address resolution protocol and forwarding IP packets. The other routers in the group are in standby state as backup roles. When the primary router fails for some reason, the backup router can be upgraded to the primary router after a short delay.

There is only one type of VRRP control message: VRRP advertisement (advertisement). It is encapsulated using IP multicast packets with a group address of 224.0.0.18 and the release range is limited to the same LAN. This ensures that virtual routers can be reused across different networks. To reduce network bandwidth consumption, only the primary router can periodically send VRRP advertisements. The backup router initiates a new round of VRRP elections after receiving VRRP for three consecutive notification intervals or receiving a notification with priority 0.

Ethernet OAM (Operation, Administration, and Maintenance) is a tool for monitoring network problems. It works at the data link layer and uses the OAM Protocol Data Units (OAM Protocol Data Units) to report the status of the network, enabling network administrators to manage the network more efficiently. By enabling the Ethernet OAM feature on two point-to-point connected devices, you can monitor the link status between the two devices for fast link detection.

With the rapid development of IP technology, various value-added services have been widely used on the Internet. Important carrier-grade services such as emerging NGN/3G, IPTV streaming media, large customer lines and VPN interconnections place high demands on the reliability of IP telecom networks.

In the prior art, as shown in FIG. 1, the router node PE3 serves as the primary router of the VRRP. As the backup router of VRRP, PE3 and PE4 receive VPLS traffic forwarding as Layer 3 traffic forwarding, and upstream traffic from PE1 to PE4 enters the switch or PTN device. Downstream traffic passes through PE3 to PE1 from the PTN device (or switch). When the VRRP switchover is performed on the primary router, the upstream and downstream traffic is normal. When the switchback is performed and the traffic path is unchanged, the traffic is interrupted. The uplink traffic does not go to the MAC address of the destination address (Media Access Control, The physical address layer) entries are not updated, and the original traffic will be sent from PE4 to PE3 to the switch (or from PE4 to the switch path), so device reliability, link reliability, and network reliability are not. high. Summary of the invention

The main object of the present invention is to provide a method and a router for solving the VPLS access L3 failover to cause a current interruption, thereby improving device reliability, link reliability, and network reliability.

The technical solution adopted by the present invention to solve the technical problem thereof is:

A method for resolving VPLS access L3 failover causes disconnection, which includes configuring VRRP on the downlink interface, the virtual address of the VRRP is used as a gateway, the uplink interface is connected through BGP, and the VPLS is established by the router node PE1 and PE2. In the L3, the BGP routing priority of the VRRP management protocol packet is the optimal route. The method includes the following steps: Configuring the BGP local preference local preference value or the path length metric value. When the VRRP active/standby relationship is formed, the BGP local preference value or the metric value is changed, so that the path advertised by the BGP route is consistent with the path of the VRRP active/standby relationship.

Preferably, after the BGP local preference value or the metric value is changed, the path of the BGP route advertised is consistent with the path of the VRRP master/slave relationship, and the steps are as follows:

The link between the VRRP master and backup routers is detected in real time through the extended management operation and maintenance EOAM, the bidirectional forwarding detection BFD, or the network detection command Ping. The detection result is notified to the VRRPo. Preferably, the method further comprises:

When the VRRP master/slave relationship changes, the BGP is notified to change its local preference value or metric value, so that the path of the BGP route advertisement is the same as the path of the VRRP master/slave relationship.

Preferably, the method further comprises:

When the VRRP master/slave relationship is switched back, the BGP is notified to change its local preference value or metric value, so that the path of the BGP route advertisement is the same as the path of the VRRP master/slave relationship.

Preferably, the change of the BGP local preference value or the metric value includes: selecting the local preference value of the BGP on the VRRP primary router plus N, and the BGP local preference value of the VRRP backup router minus N, or

Select the metric value of BGP on the VRRP master router minus N. The metric value of BGP on the VRRP backup router plus N, where: N is a natural number.

Preferably, the configuring the VRRP active/standby relationship includes:

Configure the VRRP master/slave relationship by election.

The invention provides a router, comprising:

The parameter configuration unit is configured to configure a BGP local preference value or a metric value. The path configuration unit is configured to configure a VRRP active/standby relationship. When the VRRP active/standby relationship is formed, the BGP local preference value or metric value is changed. The path of the BGP route advertisement is consistent with the path of the VRRP master/slave relationship.

Preferably, the router further includes a path detecting unit, configured to detect the link of the VRRP active and standby routers in real time through the extended management operation maintenance EOAM, the bidirectional forwarding detection BFD, or the network detection command Ping, and notify the VRRP of the detection result. .

Preferably, the router further includes a parameter change unit, when the VRRP active/standby relationship changes, notifying the BGP to change its local preference value or metric value, so that the The path of the BGP route advertisement is the same as the path of the VRRP master/slave relationship. When the VRRP relationship is switched back, the BGP is notified to change its local preference value or metric value. The path of the VRRP master/slave relationship is the same.

Preferably, the path configuration unit is configured to select the local preference value of the BGP on the VRRP primary router plus N, and the local preference value of the BGP on the VRRP backup router minus N, or

The technical solution of the present invention has the following beneficial effects: The method and the router provided by the present invention notify the association of the changed state after the detection technology discovers that the link state changes after the detection technology detects the linkage between the detection technology and the application service. Application service, application services switch state according to state changes, complete link protection, improve device reliability, link reliability and network reliability, and shorten VRPP switching time through fast detection methods such as EOAM/Ping The path of the BGP route advertisement is the same as that of the VRRP master/slave relationship. The real-time linkage is stronger. DRAWINGS

1 is a network architecture diagram provided by the prior art;

FIG. 1 is a network architecture diagram according to an embodiment of the present invention;

3 is a flowchart of a method according to an embodiment of the present invention;

4 is another flowchart of a method according to an embodiment of the present invention;

FIG. 5 is still another flowchart of a method according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a router according to an embodiment of the present disclosure;

FIG. 7 is another schematic structural diagram of a router according to an embodiment of the present disclosure;

FIG. 8 is still another schematic structural diagram of a router according to an embodiment of the present invention. The implementation, functional features, and advantages of the present invention will be further described with reference to the accompanying drawings. detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The embodiment of the present invention provides a method for resolving the VPLS access to the L3 failover, and the method is implemented as follows: As shown in FIG. 2, the VRRP is configured on the downlink interface, and the virtual address of the VRRP is used as the gateway, and the uplink interface is adopted. BGP (including: IBGP: Internal Border Gateway Protocol, EBGP: External Border Gateway Protocol, MP-IBGP: Route Switching - Internal Border Gateway Protocol, MP-EBGP: Route Switching - E-Border Border Gateway Protocol), Router Node PE1 and The router node PE2 and the PTN (or the switch) establish the VPLS, and the PE1 and the PE2 are connected to the L3 (the network layer). The BGP route priority of the router where the VRRP management protocol (master) packet is located is the optimal route. In this embodiment, The priority of a BGP route can be changed in two ways. One is: Change the local preference value. One way is to change the metric value. The change of the local preference value can only be valid in IBGP or MP-IBGP. The change of the metric value can take effect for both IBGP and EBGP. The method for solving the VPLS access L3 failover and causing the current interruption is as shown in FIG. 3:

S110. Configure a local preference value or a metric value of the BGP.

The configuration change of the local preference value can only be valid in IBGP or MP-IBGP. The configuration of the metric value can be changed for IBGP or EBGP.

S120. Configure the VRRP master/slave relationship. When the VRRP master/slave relationship is established, change the BGP local preference value or metric value to make the BGP route advertisement path consistent with the VRRP master/slave relationship.

In this step S120, the VRRP master/slave relationship is configured by election. The local preference value or the metric value of the BGP changed in the step S120, which specifically includes:

BGP route advertisement is selected according to the above configuration. The local preference value of BGP on the VRRP primary router is added with N. The local preference value of BGP on the VRRP backup router is reduced by N, or

BGP route advertisement is selected according to the above configuration. The metric value of BGP on the VRRP backup router is decremented by N, and the metric value of BGP on the VRRP backup router is added with N.

In a further embodiment, in step S120, the path of the BGP route advertisement is consistent with the path of the VRRP master/slave relationship. Then, as shown in FIG. 4, the method further includes the following steps:

The S130 detects the link of the VRRP master and backup routers in real time through EOAM (Extended Management Operation and Maintenance), BFD (Bidirectional Forwarding Detection), or Ping (Network Detection Command), and notifies the VRRP of the detection result. : Notifies the object or entity corresponding to the VRRP). The link between the VRRP master and backup routers is quickly detected, so that VRRP routes are switched more quickly, so that BGP uplink and downlink traffic is consistently avoided.

In a further embodiment, based on the foregoing embodiment, after step S130, as shown in FIG. 5, the method further includes the steps of:

S140: When the VRRP master/slave relationship changes (for example, the VRRP master router becomes the VRRP backup router), the BGP router is notified to change the local preference value or the metric value, so that the path of the BGP route advertisement is the same as the path of the VRRP master/slave relationship; or When the VRRP master/slave relationship is switched back to the VRRP master/slave relationship, the BGP router changes its local preference value or metric value to make the BGP route advertisement. The path is the same as the path of the VRRP master/slave relationship. During the change of the active/standby relationship or the switchback process: BGP route advertisement is selected according to the above configuration. Switch the VRRP switch to the local preference value of the BGP on the primary router plus N (N can be any natural number, such as: 100, 200, etc. ), The original VRRP master switch is switched to the local preference value of BGP on the standby router minus N, or

According to the above configuration, the BGP BGP route is switched to the BGP metric value of the primary router minus N. The VRRP original primary router switches to the BGP metric value plus N on the standby router.

After the detection technology detects that the link state changes, the detection technology notifies the associated application service of the changed state, and the application service performs the state according to the state change. Switching to complete link protection improves device reliability, link reliability, and network reliability, and shortens VRPP switching time through EOAM/Ping and other fast detection methods, resulting in BGP route advertisement advertised path and VRPP master-slave relationship. The path is consistent, and the linkage is more real-time.

Here, step S140 may also be performed after step S120.

The embodiment of the invention further provides a router, as shown in FIG. 6, which includes:

The parameter configuration unit 210 is configured to configure a BGP local preference value or a metric value. The path configuration unit 220 is configured to configure a VRRP active/standby relationship. When the VRRP active/standby relationship is formed, the BGP local preference value or metric value is changed, so that BGP is configured. The path of the route advertisement is the same as the path of the VRRP master/slave relationship. In a more specific embodiment, the path configuration unit 220 is configured to select the local preference value of the BGP on the VRRP primary router plus N, and the local preference value of the BGP on the VRRP backup router minus N, or

Select the metric value of BGP on the VRRP master router minus N, on the VRRP backup router.

The metric value of BGP is added to N, where: N is a natural number.

In a further embodiment, the router further includes a path detecting unit 230 for detecting the link of the VRRP active/standby router in real time through EOAM, BFD or Ping, and notifying the VRRP of the detection result.

In a further embodiment, the router further includes a parameter changing unit 240 as shown in FIG. When the VRRP master/slave relationship changes, the BGP route is notified to change the local preference value or the metric value.

When the VRRP master/slave relationship is switched back, BGP is notified to change its local preference value or metric value. The path of the BGP route advertisement is the same as the path of the VRRP master/slave relationship.

The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalents, and improvements made within the spirit and scope of the present invention should be included in the scope of the present invention. Inside.

Claims

Claim

A method for resolving a VPLS access L3 failover to cause a current interruption, comprising: configuring a virtual router redundancy protocol VRRP on a downlink interface, the virtual address of the VRRP serving as a gateway, and the uplink interface passing the border gateway protocol BGP is connected, the router node PE1 and the PE2 establish a virtual private local area network service VPLS and access the network layer L3, and the BGP route priority of the router where the VRRP management protocol packet is located is an optimal route, wherein the method includes the following steps:

Configure the BGP local preference preference value or the path length metric value. Configure the VRRP master/slave relationship. When the VRRP master/slave relationship is formed, change the BGP local preference value or metric value to advertise the BGP route. The path is the same as the path of the VRRP master/slave relationship.

The method of claim 1, wherein the step of: changing the BGP local preference value or the metric value, after the path of the BGP route advertisement is consistent with the path of the VRRP master-slave relationship, the method further includes the following steps:

The VRRP and the network detection command are used to detect the link between the VRRP master and backup routers in real time, and notify the VRRPo of the detection result.

The method of claim 2, wherein the method further comprises: when the VRRP master/slave relationship changes, notifying the BGP to change its local preference value or metric value, so that the BGP route advertisement is advertised. The path is the same as the path of the VRRP master/slave relationship.

The method of claim 2, wherein the method further comprises: when the VRRP active/standby relationship is switched back, notifying the BGP to change its local preference value or metric value, so that the BGP route advertisement is advertised. The path is the same as the path of the VRRP master/slave relationship.

The method of claim 1, wherein the changing the local preference value or the metric value of the BGP includes:

Add the local preference value of BGP on the VRRP master router plus N, and the local preference value of BGP on the VRRP backup router minus N, or

The method of claim 1, wherein the configuring the VRRP master/slave relationship comprises: configuring the VRRP master/slave relationship by means of an election.

7. A router, comprising:

The router according to claim 7, further comprising a path detecting unit, configured to detect the link of the VRRP active and standby routers in real time through the extended management operation maintenance EOAM, the bidirectional forwarding detection BFD, or the network detection command Ping. , and notify the VRPPO of the test result

The router according to claim 8, further comprising a parameter changing unit, when the VRRP active/standby relationship changes, notifying the BGP to change its local preference value or metric value, so that the BGP route is The advertised path is the same as the path of the VRRP master/slave relationship.

The method according to claim 7, wherein the path configuration unit is configured to: Add the local preference value of BGP to the VRRP master router plus N. The local preference value of BGP on the VRRP backup router minus N, or