CN102457586B - Expanding method for realizing double-layer network and expanded double-layer network - Google Patents

Abstract

The invention discloses an extension method for implementing a two-layer network and an extended two-layer network. An address resolution server (ARS) is set in an operator network, and a virtual switch is set on a physical server in a data center; the virtual switch is in After the virtual machine in the physical server is powered on, it registers with the ARS the correspondence between the IP address of the virtual machine and its own MAC address; the ARS records the IP address of the virtual machine registered by the virtual switch and the virtual The corresponding relationship of the MAC address of the switch is for other virtual machines to query; the virtual machine in the physical server queries the MAC address corresponding to the IP address from the ARS according to the IP address of the communication peer, and communicates with the communication peer through the MAC address Terminals exchange messages. The Layer 2 network reduces the overhead of the Address Resolution Protocol and avoids the impact of broadcast storms, thus greatly improving the scalability of the Layer 2 network.

Description

An extension method for implementing a two-layer network and the extended two-layer network

technical field

The invention relates to a two-layer network, in particular to an extension method for realizing the two-layer network and the extended two-layer network.

Background technique

In the current IP local area network, IPV4 uses ARP (Address Resolution Protocol, Address Resolution Protocol), and IPV6 uses NDP (Neighbor Discovery Protocol, Neighbor Discovery Protocol) to obtain the address of the layer-2 network. The mechanism of address discovery is basically the same between the two, and both use Layer 2 broadcast to obtain the data link layer address corresponding to the destination IP address. For Ethernet, the data link layer address corresponds to the MAC (Media Access Control, Media Access Control) address. Each host maintains an independent cache and presets the aging timing time. When sending an IP message, for the destination IP address that is not recorded in the local cache, an ARP/NDP message must be broadcast in the LAN to query the address of the destination IP address. The corresponding data link layer address.

When the number of hosts in the local area network is very large, such as a large data center, or even a cross-regional L2VPN connected by L2VPN (Layer 2 Virtual Private Network) technology, the number of hosts can reach thousands or even tens of thousands. Applications make this situation worse. Using virtualization technology, a physical machine can support dozens of virtual hosts, and in the future it can support up to hundreds of virtual hosts. Each virtual host has its own independent IP address and MAC address. Although VLAN (Virtual Local Area Network) division can be used to isolate broadcast storms (VLAN includes port-based VLAN and MAC-based VLAN), the virtual machine migration technology brought about by virtualization technology requires the host itself, IP address and The MAC address can be completely floated, so neither port-based VLAN nor MAC-based VLAN can be used.

OTV (Overlay Transport Virtualization, overlay network transmission virtualization) technology, compared with ordinary L2VPN technology, the broadcast storm between different L2VPN sites is isolated, and the broadcast is limited to the data center at the same physical location. But even in a data center, the number of virtual hosts can still reach tens of thousands or even hundreds of thousands, and ARP/NDP broadcasts will still greatly affect network performance, and the size of the MAC forwarding table of each layer 2 switch is also limited , it is difficult to support such a large-scale two-layer network.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for realizing the expansion of the two-layer network and the expanded two-layer network, and solve the problem of broadcast storm generated during the process of obtaining the MAC address corresponding to the destination IP address by the host.

In order to solve the above-mentioned technical problems, a kind of method of realizing two-layer network extension of the present invention, address resolution server (ARS) is set in operator's network, and virtual exchange is set on the physical server in data center;

After the virtual machine in the physical server is powered on, the virtual switch registers with the ARS the correspondence between the IP address of the virtual machine and its own MAC address;

The ARS records the corresponding relationship between the IP address of the virtual machine registered by the virtual switch and the MAC address of the virtual switch for other virtual machines to query;

The virtual machine in the physical server queries the MAC address corresponding to the IP address from the ARS according to the IP address of the communication peer, and exchanges messages with the communication peer through the MAC address.

Further, registering the correspondence between the IP address of the virtual machine and its own MAC address with the ARS by the virtual switch includes:

After the virtual machine is powered on, the virtual switch records the correspondence between the virtual machine's IP address and the MAC address, and registers the virtual machine's IP address and the MAC address with the access service router (ASR) to which the virtual switch belongs. The correspondence between the MAC addresses of the virtual switches;

The ASR records the correspondence between the IP address of the virtual machine and the MAC address of the virtual switch, and registers the correspondence and the address of the ASR with the ARS.

Further, when the ARS records the correspondence between the IP address of the virtual machine registered by the virtual switch and the MAC address of the virtual switch, it also correspondingly records the address of the ASR.

Further, the virtual machine in the physical server querying the MAC address corresponding to the IP address from the ARS according to the IP address of the communication peer includes:

The virtual machine in the physical server sends a MAC address resolution broadcast request, the virtual switch in the physical server converts the broadcast request into a unicast query request, and uses the unicast query request to query the communication pair from the ARS The MAC address corresponding to the IP address of the client.

Further, the virtual switch machine uses the unicast query request to query the MAC address corresponding to the IP address of the communication peer from the ARS, including:

The virtual switch sends the unicast query request to the ASR to which the virtual switch belongs, and queries the MAC address corresponding to the IP address of the communication peer through the ASR;

After receiving the query request, the ASR to which the virtual switch belongs queries the ARS for the MAC address corresponding to the IP address of the communication peer, and the ARS queries and returns the queried MAC address and the attribution of the communication peer. The address of the ASR, the ASR to which the virtual switch belongs saves the received MAC address and the address of the ASR, and returns its own MAC address to the virtual switch when the received address of the ASR is not its own address;

The virtual switch notifies the virtual machine in the physical server that the MAC address corresponding to the IP address of the communication peer is the address of the ASR to which the virtual switch belongs.

Further, the message exchange between the virtual machine in the physical server and the communication peer through the MAC address includes:

The virtual machine in the physical server sends a message to the communication peer, and the source MAC address and destination MAC address of the message are respectively the MAC address of the virtual machine and the address of the ASR to which the virtual switch belongs;

After receiving the message, the virtual switch modifies the source MAC address of the message to the MAC address of the virtual switch, and sends the message to the ASR to which the virtual switch belongs according to the destination MAC address;

The ASR to which the virtual switch belongs locally queries the MAC address of the communication peer and the address of the ASR to which the communication peer belongs, modifies the destination MAC address of the message to the MAC address of the communication peer that has been queried, and sends the report The text is encapsulated into a tunnel whose destination address is the address of the ASR to which the communication peer belongs, and sent to the ASR to which the communication peer belongs through the operator network.

Further, the method also includes:

After receiving the message, the ASR belonging to the communication peer releases the tunnel, and sends the message to the virtual switch on the physical server where the communication peer is located according to the destination MAC address of the message. The IP address queries the MAC address of the communication peer, modifies the destination MAC address of the message to the MAC address of the communication peer, and sends it to the communication peer.

Further, the virtual machine in the physical server querying the MAC address corresponding to the IP address from the ARS according to the IP address of the communication peer includes:

The virtual switch sends the unicast query request to the ASR to which the virtual switch belongs, and queries the MAC address corresponding to the IP address of the communication peer through the ASR;

After receiving the query request, the ASR to which the virtual switch belongs queries the ARS for the MAC address corresponding to the IP address of the communication peer, and the ARS queries and returns the queried MAC address and the attribution of the communication peer. The address of the ASR, the ASR to which the virtual switch belongs saves the received MAC address and the address of the ASR, and returns the received MAC address to the virtual switch when the received address of the ASR is its own address;

The virtual switch notifies the virtual machine in the physical server that the MAC address corresponding to the IP address of the communication peer is the MAC address received by the ASR to which the virtual switch belongs.

Further, the message exchange between the virtual machine in the physical server and the communication peer through the MAC address includes:

The virtual machine in the physical server sends a message to the communication peer, and the source MAC address and destination MAC address of the message are respectively the MAC address of the virtual machine and the MAC address received by the ASR to which the virtual switch belongs ;

After the virtual switch receives the message, it modifies the source MAC address of the message to the MAC address of the virtual switch, and sends the message to the communication peer through the layer-2 switch according to the destination MAC address Virtual switch on the same physical server.

Further, the method also includes:

The virtual switch on the physical server where the communication peer is located queries the MAC address of the communication peer, modifies the destination MAC address of the message to the queried MAC address of the communication peer, and sends it to the communication peer.

Further, the virtual switch is set in the virtual machine manager of the physical server in the data center.

Further, a physical server, a virtual machine is installed in the physical server, and a virtual switch is also set on the physical server;

The virtual switch is configured to, after the virtual machine in the physical server is powered on, register the correspondence between the IP address of the virtual machine and its own MAC address with an Address Resolution Server (ARS) set in the operator's network.

Further, registering the correspondence between the IP address of the virtual machine and its own MAC address with the ARS by the virtual switch includes:

After the virtual machine is powered on, the virtual switch records the correspondence between the virtual machine's IP address and the MAC address, and registers the virtual machine's IP address and the MAC address with the access service router (ASR) to which the virtual switch belongs. Correspondence between MAC addresses of virtual switches.

Further, the virtual switch is also configured to convert the broadcast request into a unicast query request after receiving the MAC address resolution broadcast request sent by the virtual machine in the physical server, and use the unicast query request to convert the The ARS queries the MAC address corresponding to the IP address of the communication peer.

Further, the virtual switch machine uses the unicast query request to query the MAC address corresponding to the IP address of the communication peer from the ARS, including:

The virtual switch sends the unicast query request to the ASR to which the virtual switch belongs, through which the ASR queries the MAC address corresponding to the IP address of the communication peer, and the ASR returns the address of the ASR or the After the address of the virtual switch on the physical server where the communication peer is located, correspondingly notify the virtual machine in the physical server that the MAC address corresponding to the IP address of the communication peer is the address of the ASR to which the virtual switch belongs or the address of the communication peer The address of the virtual switch on the physical server where it resides.

Further, the virtual switch is also used to receive a message sent by the virtual machine to the communication peer, the source MAC address of the message is the MAC address of the virtual machine, and the destination MAC address is the address to which the virtual switch belongs. The address of the ASR or the address of the virtual switch on the physical server where the communication peer is located. After receiving the message, the virtual switch modifies the source MAC address of the message to the MAC address of the virtual switch, and according to The destination MAC address sends the message to the ASR to which the virtual switch belongs or the virtual switch on the physical server where the communication peer is located.

Further, the virtual switch is also configured to query the corresponding MAC address according to the destination IP address of the packet when receiving the packet sent by the belonging ASR, and modify the destination MAC address of the packet to the queried MAC address. address and send it.

Further, an access service router (ASR), including: a registration module, wherein:

The registration module is used to record the corresponding relationship between the IP address of the virtual machine registered by the virtual switch and the MAC address of the virtual switch, and register the corresponding relationship and the address of the ASR with an address resolution server (ARS).

Further, the ASR also includes an address query module, wherein:

The address query module is configured to query the ARS for the MAC address corresponding to the IP address of the communication peer of the virtual machine after receiving the query request of the virtual switch, and store the received MAC address and the address of the ASR, When the address of the received ASR is not the address of the ASR where the address query module is located, return the address of the ASR where the address query module is located to the virtual switch; the address of the received ASR is the address of the ASR where the address query module is located address, return the received MAC address to the virtual switch.

Further, the ASR also includes a message forwarding module, wherein:

The message forwarding module is configured to, when receiving a message sent by the virtual switch, locally query the MAC address of the communication peer and the address of the ASR to which the communication peer belongs, and transfer the destination MAC address of the message to The address is modified to query the MAC address of the communication peer, and the message is encapsulated into a tunnel whose destination address is the address of the ASR to which the communication peer belongs, and sent to the ASR to which the communication peer belongs via the operator network.

Further, the message forwarding module is further configured to release the tunnel after receiving the message sent through the operator network, and send the message to the virtual switch on the physical server according to the destination MAC address of the message.

Further, an extended two-layer network includes an operator network and a data center, an address resolution server (ARS) is set in the operator network, and a virtual switch is set on a physical server in the data center, wherein:

The virtual switch is configured to register the correspondence between the IP address of the virtual machine and its own MAC address with the ARS after the virtual machine in the physical server is powered on;

The ARS is used to record the corresponding relationship between the IP address of the virtual machine registered with the virtual switch and the MAC address of the virtual switch for other virtual machines to query;

The virtual machine in the physical server is configured to query the MAC address corresponding to the IP address from the ARS according to the IP address of the communication peer, and exchange messages with the destination virtual machine through the MAC address.

Further, the layer-2 network further includes: an access service router (ASR) for establishing intercommunication between the user data center and the operator network, wherein:

When the virtual switch registers the corresponding relationship between the IP address of the virtual machine and its own MAC address with the ARS, after receiving the registration of the virtual switch, record the IP address of the virtual machine and the address of the virtual switch. The corresponding relationship of the MAC address, and register the corresponding relationship and the address of the ASR with the ARS.

Further, the ASR is also used to locally query the MAC address of the communication peer and the address of the ASR to which the communication peer belongs when receiving the message sent by the virtual switch, and set the purpose of the message to The MAC address is modified to be the MAC address of the communication peer, and the message is encapsulated into a tunnel whose destination address is the address of the ASR to which the communication peer belongs, and sent to the ASR to which the communication peer belongs through the operator network.

Further, the ARS is further configured to correspondingly record the address of the home ASR when recording the correspondence between the IP address of the virtual machine registered with the virtual switch and the MAC address of the virtual switch.

Further, the virtual machine in the physical server querying the MAC address corresponding to the IP address from the ARS according to the IP address of the communication peer includes:

The virtual machine in the physical server sends a MAC address resolution broadcast request, the virtual switch in the physical server converts the broadcast request into a unicast query request, and uses the unicast query request to query the communication from the ARS MAC address corresponding to the peer IP address.

Utilizing the invention, the two-layer network reduces the overhead of the address resolution protocol, avoids the influence of broadcast storms, and thus can greatly improve the scalability of the two-layer network.

Description of drawings

Fig. 1 is a system architecture diagram of the present embodiment;

Fig. 2 is a structural diagram inside a physical machine in the two-layer network of the present embodiment;

Fig. 3 is the flow chart of the virtual machine MAC address registration of this embodiment;

FIG. 4 is a flow chart of establishing communication between two virtual machines across data centers in this embodiment;

FIG. 5 is a flow chart of establishing communication between two virtual machines in the same data center in this embodiment;

FIG. 6 is a structural diagram of the access service router in this embodiment.

Detailed ways

Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

In this embodiment, the ARP/NDP protocol is improved, combined with the L2VPN technology, to implement a layer 2 network that is scalable and can support a large number of virtual machines.

Figure 1 shows the network architecture of this embodiment, which includes multiple data centers and operator networks responsible for interconnection. The data centers and operator networks are connected through ASR (Access Service Router, Access Service Router). The center includes several physical servers and Layer 2 switches, and each physical server is equipped with a virtual machine manager (VMM), which is responsible for the management of several virtual machines on the physical server.

In this embodiment, the existing operating system on the Layer 2 switch and the virtual machine in the data center is not modified, a virtual switch (vSwitch) is added in the virtual machine manager, and the access service router (also called the data center border router) is modified. Also introduced ARS (Address Resolution Server, address resolution server, also known as MAC address resolution database), responsible for receiving the registration and query of the second layer address.

After the virtual machine is powered on, the virtual switch records the correspondence between the virtual machine's IP address and the MAC address, and requests the ARS to register the correspondence, and the virtual switch modifies the MAC address in the correspondence to its own MAC address, that is to say Register the corresponding relationship between the IP address of the virtual machine and the MAC address of the virtual switch itself with ARS. At this time, all the virtual machines in the physical server managed by a VMM only present one MAC address to the outside, which greatly reduces the number of Layer 2 switching in the network. The size of the MAC forwarding table in the device.

ARS records the registered MAC address, IP address, and IP address of the ASR to which the virtual machine belongs for subsequent query.

When the VM needs to communicate with other hosts, the existing operating system of the virtual machine still uses the broadcast ARP/NDP protocol to query the MAC address. This broadcast request is intercepted by the virtual switch in the VMM and converted into a unicast query message to the ARS. , the message passes through the ASR, and the ASR can convert the format of the message and store the relevant parameter content. After receiving the unicast query message, the ARS returns the MAC address corresponding to the IP address of the target virtual machine and the MAC address of the ASR to which it belongs.

Since the MAC address registered by the VM in ARS is actually the MAC address of the virtual switch, the address obtained by the query party is also the address of the virtual switch. After the source virtual machine obtains the MAC address from the query, it will send a packet to the destination virtual machine. When the message arrives at the virtual switch where the destination virtual machine is located, the virtual switch searches the local database to obtain the real MAC address of the destination virtual machine, modifies the destination MAC address to the real MAC address of the destination virtual machine, and then sends it to the operating system in the virtual machine.

When the source virtual machine and the destination virtual machine do not belong to the same data center, ASR will change the MAC address of the target virtual machine in the query response to the MAC address of the ASR, and record the IP address and registered MAC address of the destination virtual machine In this way, after the source virtual machine obtains the query response, the destination MAC address of the message sent is the MAC address of the ASR to which the data center belongs, ensuring that the belonging ASR can intercept the message. When the ASR receives the destination MAC address as its own After the packet with the MAC address, take out the destination IP address in the packet, query the local database, obtain the registered MAC address corresponding to the destination IP and the MAC address belonging to the ASR, and change the destination MAC address of the original packet to the one corresponding to the destination virtual machine. Register the MAC address and encapsulate it in an IP in IP tunnel whose outer address is the MAC address of the destination virtual machine's ASR (destination ASR). The tunnel can also be a GRE (Generic Routing Encapsulation, general routing encapsulation) form ; When the destination ASR receives the message, it removes the outer encapsulation header, takes out the original data message, and sends it to the virtual switch corresponding to the destination MAC address.

ARS can be deployed centrally in the operator's network or built using distributed technology; it can also be deployed inside the data center, where ARS servers in multiple data centers form a logically integrated distributed server system.

In order to maintain the validity of the MAC address, the virtual switch should replace the virtual machine to perform periodic address registration refresh. ARS maintains an aging timer for each address. When no refresh request is received within the timer period, the address record will be released.

Figure 1 is a system architecture diagram of this embodiment, the system includes multiple data centers 101, each data center includes multiple physical servers 102 and multiple layer 2 switches 103; the operator network 104 connects multiple data centers, including Core router 106 and ARS 107 for handling layer 2 address registration and query; ASR 105 is an access service router connecting the data center and the carrier network. The Unicast Address Mapping Protocol (uMAP) runs between the ASR and the ARS.

Fig. 2 is the internal architecture of a physical server in the virtual machine pool, 201 is the physical machine hardware; 202 is the virtual machine manager, is responsible for the virtual machine creation, revocation and scheduling of the physical machine; 203 is for the virtual machine defined in this embodiment The switch is responsible for registering the MAC address instead of the virtual machine, converting the broadcast ARP request into a unicast MAC query, etc.; 204 is the migration manager in the VMM, which is not concerned in this article; 205 is the virtual machine managed by the VMM; 206 is the virtual machine The operating system in the virtual machine; 207 is various application programs running on the operating system in the virtual machine.

Fig. 3 shows the MAC address registration process of this embodiment, including:

Step 301: the virtual machine manager in the physical server controls the virtual machine VM11 to be powered on;

Step 302: After the power-on operation is completed, VM11 initiates the process of obtaining the IP address configuration;

The virtual machine VM11 obtains an IP address through DHCP (Dynamic Host Configuration Protocol) or other methods.

Step 303: vSwitch1 residing in the VMM learns that VM11 has completed the IP address configuration process by checking the IP address automatic configuration message, and records the correspondence between the IP address and MAC of VM11 locally, where the IP address and MAC address of VM11 The addresses are IP11 and MAC11 respectively, and a MAC address registration request is sent to ARS to register the corresponding relationship between IP11 and vSwitch1's own MAC address (MAC1), and the request passes through the home ASR;

The source IP address and source MAC address of the MAC address registration request are IP11 and MAC1 respectively.

The MAC address MAC11 of VM11 is allocated by the VMM when VM11 is powered on.

Step 304: the middle layer 2 switch learns MAC1 by checking the source MAC address of the MAC address registration request, and records it in the MAC-port forwarding table;

This step is standard behavior for Layer 2 switches.

Step 305: the Layer 2 switch forwards the MAC address registration request to the ASR;

Step 306: After the ASR receives the MAC address registration request, it records the corresponding relationship of <MAC1, IP11> locally to prepare for subsequent message forwarding;

Step 307: The ASR sends an address mapping registration request to the ARS, which includes the <MAC1, IP11> binding relationship and the ASR's own IP address;

Step 308: ARS records the MAC, IP address and IP address of the ASR to which the virtual machine belongs, etc. carried in the address mapping registration request, for subsequent query use;

Step 309: The ARS returns a successful response to the ASR, and the response is forwarded to the vSwitch1 that initiates the registration. The address registration process is complete.

FIG. 4 shows an embodiment of establishing communication between two virtual machines across data centers, and the specific process is as follows:

Step 401: The virtual machine VM21 located in the data center 2 needs to communicate with the virtual machine VM11 located in the data center 1. There is no MAC record corresponding to the IP address of VM11 in the local ARP cache, and VM21 sends a common ARP broadcast request;

Here, both VM11 and VM21 have been powered on successfully, and the vSwitch where they are located has correctly registered the correspondence between the IP address and the MAC address with the ARS.

Step 402: The ARP broadcast request is intercepted by the virtual switch vSWitch2 on the physical machine where VM21 is located, and vSWitch2 converts it into a unicast ARP query request and sends it to ASR2 through the Layer 2 switch. The query target of the query request is the IP address IP11 of VM11;

Step 403: After receiving the unicast ARP query request, ASR2 generates a Map_Request (mapping query) request and sends it to ARS to query the MAC address corresponding to IP11;

In this embodiment, it is assumed that the query protocol from the ASR to the ARS is different from the unicast ARP query request of the vSwitch, and the actual protocol definition can also be reused.

Step 404: ARS queries the local database to obtain the MAC address corresponding to IP11 and the address belonging to ASR1;

Step 405: ARS returns the MAC address, the address of ASR1 and IP11 obtained through the query to ASR2 through the Map_Reply message;

Step 406: ASR2 takes out IP, MAC and the address of ASR1 wherein after receiving the Map_Reply message, and stores it locally, and constructs an ARP unicast response message simultaneously, and its source MAC address is changed to the MAC address of ASR2, and the destination MAC address is MAC address of vSWitch2;

Step 406: ASR2 sends the ARP unicast response to vSwitch2;

Step 407: vSwitch2 constructs an ordinary ARP response according to the received ARP unicast response, and notifies VM21 that the MAC address corresponding to IP11 it inquires is the MAC address of ASR2;

Step 408: VM21 sends an IP message according to the MAC address obtained from the query, and the source and destination IP addresses and MAC addresses are respectively IP21, MAC21, IP11, and MAC_ASR2;

Step 409: vSwitch2 rewrites the source MAC address to the MAC address MAC2 of the virtual switch after receiving the IP message of VM21, and sends the message to ASR2 according to the destination MAC address of MAC_ASR2;

Step 410: ASR2 takes out the destination IP address in the message, searches the local database, and obtains the registered MAC address MAC1 corresponding to IP11 and the address IP_ASR1 of the assigned ASR1;

Step 411: ASR2 knows that the destination IP address is located in another data center according to the data in the previous step, it changes the destination MAC address of the original message to the MAC1 obtained in step 406, and encapsulates the message in a destination IP address of Send to ASR1 in the tunnel of ASR1's IP address;

The tunnel can be a simple IP in IP tunnel, a GRE tunnel, or any other form of tunnel.

Step 412: After receiving the message, ASR1 removes the header of the outer tunnel message and restores the original message;

Step 413: ASR1 sends the message to vSwitch1 according to the destination MAC address of the message;

Step 414: vSwitch1 searches the local database, learns that the real MAC address corresponding to the destination IP address IP11 in the message is MAC11, rewrites the layer 2 message header to MAC11, and sends the message to the protocol stack of the operating system in VM11. At this point, the establishment of IP communication is completed.

FIG. 5 shows an embodiment of establishing communication between two virtual machines in the same data center, and the specific process is as follows:

Step 501: The virtual machine VM21 located in the physical machine 2 needs to communicate with the virtual machine VM11 located in the physical machine 1. There is no MAC record corresponding to the IP address of VM11 in the local ARP cache, and it sends a common ARP broadcast request;

Here, VM11 and VM21 have been powered on successfully, and the vSwitch where they are located has correctly registered their own IP addresses and MAC correspondences with the ARS.

Step 502: The ARP broadcast request is intercepted by the virtual switch vSwitch2 on the physical machine where it is located, and vSwitch2 converts it into a unicast ARP query request and sends it to ASR1. The target of the query request is the IP address IP11 of VM11;

Step 503: After receiving the unicast ARP query request, ASR1 generates a Map_Request request and sends it to ARS to query the MAC address corresponding to IP11;

In this embodiment, it is assumed that the query protocol from the ASR to the ARS is different from the ARP unicast query request of the vSwitch, and the actual protocol definition can also be reused.

Step 504: ARS queries the local database to obtain the MAC address corresponding to IP11 and the address of ASR1.

Step 505: ARS returns the obtained MAC address, ASR1 address and IP11 to ASR1 through a Map_Reply message;

Step 506: After receiving the Map_Reply message, ASR1 takes out the IP, MAC and ASR1 address, stores them locally, and constructs an ARP unicast response message at the same time. ASR1 notices that the destination ASR of the virtual machine is itself, so the ARP The IP and MAC addresses of the unicast response message are taken from the Map_Reply message and will not be modified;

Step 507: vSwitch constructs an ordinary ARP response according to the unicast response, and notifies VM21 that the MAC address corresponding to IP11 it inquires is MAC1;

Step 508: VM21 sends an IP packet according to the MAC address obtained in the previous query, and the source and destination IP addresses and MAC addresses are respectively IP21, MAC21, IP11 and MAC1;

Step 509: vSwitch2 rewrites the source MAC address to the address MAC2 of the virtual switch after receiving the IP message of VM21, and the Layer 2 switch sends the message to physical machine 1 according to the destination MAC address of MAC1;

Step 510: vSwitch1 on physical machine 1 receives the message, searches the local database, and learns that the real MAC address corresponding to the destination IP address IP11 in the message is MAC11, rewrites the header of the layer-2 message to MAC11, and converts the message to Sent to the protocol stack of the operating system in VM11. So far, the establishment of IP communication is completed.

Fig. 6 is the structural diagram of the ASR of this embodiment, including: registration module, address query module and message forwarding module, wherein:

The registration module is used to record the corresponding relationship between the IP address of the virtual machine registered by the virtual switch and the MAC address of the virtual switch, and register the corresponding relationship and the address of the ASR with the address resolution server (ARS).

The address query module is used to query the ARS for the MAC address corresponding to the IP address of the communication peer of the virtual machine after receiving the query request of the virtual switch, and save the received MAC address and the address of the ASR, and then in the received ASR When the address of the address query module is not the address of the ASR where the address query module is located, return the address of the ASR where the address query module is located to the virtual switch; to the MAC address.

The message forwarding module is used to locally query the MAC address of the communication peer and the address of the ASR to which the communication peer belongs when receiving a message sent by the virtual switch, and modify the destination MAC address of the message to the address of the query to the communication peer. MAC address, and encapsulate the message into a tunnel whose destination address is the address of the ASR of the communication peer, and send it to the ASR of the communication peer through the operator network, and after receiving the message sent through the operator network , release the tunnel, and send the packet to the virtual switch on the physical server according to the destination MAC address of the packet.

Those of ordinary skill in the art can understand that all or part of the steps in the above method can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, such as a read-only memory, a magnetic disk, or an optical disk. Optionally, all or part of the steps in the foregoing embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module in the foregoing embodiments may be implemented in the form of hardware, or may be implemented in the form of software function modules. The present invention is not limited to any specific combination of hardware and software.

Certainly, the present invention can also have multiple implementation modes, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes or changes according to the present invention, but all Any modifications, equivalent replacements, and improvements made within the spirit and principles shall be included within the protection scope of the present invention.

Claims (19)

1. A method for realizing two-layer network expansion is characterized in that, an address resolution server (ARS) is set in the carrier network, and a virtual switch is set on the physical server in the data center; After the virtual machine in the physical server is powered on, the virtual switch registers with the ARS the correspondence between the IP address of the virtual machine and its own MAC address; The ARS records the corresponding relationship between the IP address of the virtual machine registered by the virtual switch and the MAC address of the virtual switch for other virtual machines to query; The virtual machine in the physical server queries the MAC address corresponding to the IP address from the ARS according to the IP address of the communication peer, and exchanges messages with the communication peer through the MAC address; Wherein, the virtual machine in the physical server querying the MAC address corresponding to the IP address from the ARS according to the IP address of the communication peer includes: The virtual machine in the physical server sends a MAC address resolution broadcast request, the virtual switch in the physical server converts the broadcast request into a unicast query request, and uses the unicast query request to query the communication pair from the ARS The MAC address corresponding to the IP address of the terminal; Wherein, the virtual switch uses the unicast query request to query the MAC address corresponding to the IP address of the communication peer from the ARS, including: The virtual switch sends the unicast query request to the access service router (ASR) to which the virtual switch belongs, and queries the MAC address corresponding to the IP address of the communication peer through the ASR; After receiving the query request, the ASR to which the virtual switch belongs queries the ARS for the MAC address corresponding to the IP address of the communication peer, and the ARS queries and returns the queried MAC address and the attribution of the communication peer. The address of the ASR to which the virtual switch belongs, the ASR to which the virtual switch belongs saves the received MAC address and the address of the ASR to which the communication peer belongs, and when the received address of the ASR to which the communication peer belongs is not its own address, returning its own MAC address to the virtual switch; The virtual switch notifies the virtual machine in the physical server that the MAC address corresponding to the IP address of the communication peer is the address of the ASR to which the virtual switch belongs. 2. The method according to claim 1, wherein the virtual switch registering the correspondence between the IP address of the virtual machine and its own MAC address with the ARS comprises: After the virtual machine is powered on, the virtual switch records the correspondence between the virtual machine's IP address and the MAC address, and registers the virtual machine's IP address with the virtual switch with the access service router (ASR) to which the virtual switch belongs. The corresponding relationship of the MAC address; The ASR records the correspondence between the IP address of the virtual machine and the MAC address of the virtual switch, and registers the correspondence and the address of the ASR with the ARS. 3. The method according to claim 2, wherein when the ARS records the correspondence between the IP address of the virtual machine registered by the virtual switch and the MAC address of the virtual switch, it also correspondingly records the IP address of the ASR. address. 4. The method according to claim 1, wherein the message exchange between the virtual machine in the physical server and the communication peer through the MAC address comprises: The virtual machine in the physical server sends a message to the communication peer, and the source MAC address and destination MAC address of the message are respectively the MAC address of the virtual machine and the address of the ASR to which the virtual switch belongs; After receiving the message, the virtual switch modifies the source MAC address of the message to the MAC address of the virtual switch, and sends the message to the ASR to which the virtual switch belongs according to the destination MAC address; The ASR to which the virtual switch belongs locally queries the MAC address of the communication peer and the address of the ASR to which the communication peer belongs, modifies the destination MAC address of the message to the MAC address of the communication peer that has been queried, and sends the report The text is encapsulated into a tunnel whose destination address is the address of the ASR to which the communication peer belongs, and sent to the ASR to which the communication peer belongs through the operator network. 5. The method of claim 4, further comprising: After receiving the message, the ASR belonging to the communication peer releases the tunnel, and sends the message to the virtual switch on the physical server where the communication peer is located according to the destination MAC address of the message. The IP address queries the MAC address of the communication peer, modifies the destination MAC address of the message to the MAC address of the communication peer, and sends it to the communication peer. 6. The method according to claim 1, wherein the virtual machine in the physical server querying the MAC address corresponding to the IP address from the ARS according to the IP address of the communication peer comprises: The virtual switch sends the unicast query request to the ASR to which the virtual switch belongs, and queries the MAC address corresponding to the IP address of the communication peer through the ASR; After receiving the query request, the ASR to which the virtual switch belongs queries the ARS for the MAC address corresponding to the IP address of the communication peer, and the ARS queries and returns the queried MAC address and the attribution of the communication peer. The address of the ASR, the ASR to which the virtual switch belongs saves the received MAC address and the address of the ASR, and returns the received MAC address to the virtual switch when the received address of the ASR is its own address; The virtual switch notifies the virtual machine in the physical server that the MAC address corresponding to the IP address of the communication peer is the MAC address received by the ASR to which the virtual switch belongs. 7. The method according to claim 6, wherein the message exchange between the virtual machine in the physical server and the communication peer through the MAC address comprises: The virtual machine in the physical server sends a message to the communication peer, and the source MAC address and destination MAC address of the message are respectively the MAC address of the virtual machine and the MAC address received by the ASR to which the virtual switch belongs ; After the virtual switch receives the message, it modifies the source MAC address of the message to the MAC address of the virtual switch, and sends the message to the communication peer through the layer-2 switch according to the destination MAC address Virtual switch on the same physical server. 8. The method of claim 7, further comprising: The virtual switch on the physical server where the communication peer is located queries the MAC address of the communication peer, modifies the destination MAC address of the message to the queried MAC address of the communication peer, and sends it to the communication peer. 9. The method according to claim 1, wherein the virtual switch is set in a virtual machine manager of a physical server in the data center. 10. A kind of physical server, virtual machine is installed in this physical server, it is characterized in that, also be provided with virtual switch on this physical server; The virtual switch is configured to register the correspondence between the IP address of the virtual machine and its own MAC address with the address resolution server ARS set in the operator network after the virtual machine in the physical server is powered on; The virtual switch is further configured to convert the broadcast request into a unicast query request after receiving the MAC address resolution broadcast request sent by the virtual machine in the physical server, and use the unicast query request to send the MAC address resolution request from the ARS Query the MAC address corresponding to the IP address of the communication peer; The virtual switch uses the unicast query request to query the MAC address corresponding to the IP address of the communication peer from the ARS, including: The virtual switch sends the unicast query request to the access service router ASR to which the virtual switch belongs, queries the MAC address corresponding to the IP address of the communication peer through the ASR, and returns the ASR's address in the ASR. address or the address of the virtual switch on the physical server where the communication peer is located, correspondingly notify the virtual machine in the physical server that the MAC address corresponding to the IP address of the communication peer is the address of the ASR to which the virtual switch belongs Or the address of the virtual switch on the physical server where the communication peer is located. 11. The physical server according to claim 10, wherein the virtual switch registering with the ARS the correspondence between the IP address of the virtual machine and its own MAC address comprises: After the virtual machine is powered on, the virtual switch records the correspondence between the virtual machine's IP address and the MAC address, and registers the virtual machine's IP address with the virtual switch with the access service router (ASR) to which the virtual switch belongs. The corresponding relationship between MAC addresses. 12. The physical server according to claim 10, characterized in that: The virtual switch is further configured to receive a message sent by the virtual machine to the communication peer, the source MAC address of the message is the MAC address of the virtual machine, and the destination MAC address is the address of the ASR to which the virtual switch belongs Or the address of the virtual switch on the physical server where the communication peer is located, after receiving the message, the virtual switch modifies the source MAC address of the message to the MAC address of the virtual switch, and according to the destination MAC address The message is sent to the ASR to which the virtual switch belongs or the virtual switch on the physical server where the communication peer is located. 13. The physical server according to claim 12, characterized in that: The virtual switch is also configured to query the corresponding MAC address according to the destination IP address of the message when receiving the message sent by the belonging ASR, modify the destination MAC address of the message to the queried MAC address, and to send. 14. An access service router ASR, comprising: a registration module and an address query module, wherein: The registration module is used to record the corresponding relationship between the IP address of the virtual machine registered by the virtual switch and the MAC address of the virtual switch, and register the corresponding relationship and the address of the ASR with the address resolution server ARS; The address query module is configured to query the ARS for the MAC address corresponding to the IP address of the communication peer of the virtual machine after receiving the query request of the virtual switch, and store the received MAC address and the address of the ASR, When the address of the received ASR is not the address of the ASR where the address query module is located, return the address of the ASR where the address query module is located to the virtual switch; the address of the received ASR is the address of the ASR where the address query module is located address, return the received MAC address to the virtual switch. 15. The access service router according to claim 14, wherein the ASR further comprises a message forwarding module, wherein: The message forwarding module is configured to, when receiving a message sent by the virtual switch, locally query the MAC address of the communication peer and the address of the ASR to which the communication peer belongs, and transfer the destination MAC address of the message to The address is modified to query the MAC address of the communication peer, and the message is encapsulated into a tunnel whose destination address is the address of the ASR to which the communication peer belongs, and sent to the ASR to which the communication peer belongs via the operator network. 16. The access service router according to claim 15, characterized in that: The message forwarding module is further configured to release the tunnel after receiving the message sent through the operator network, and send the message to the virtual switch on the physical server according to the destination MAC address of the message. 17. An extended two-layer network, including an operator network and a data center, characterized in that an address resolution server ARS is set in the operator network, and a virtual switch is set on a physical server in the data center, wherein : The virtual switch is configured to register the correspondence between the IP address of the virtual machine and its own MAC address with the ARS after the virtual machine in the physical server is powered on; The ARS is used to record the corresponding relationship between the IP address of the virtual machine registered with the virtual switch and the MAC address of the virtual switch for other virtual machines to query; The virtual machine in the physical server is configured to query the MAC address corresponding to the IP address from the ARS according to the IP address of the communication peer, and exchange messages with the communication peer through the MAC address; The two-layer network also includes: an access service router ASR for establishing intercommunication between the data center and the operator network, wherein: When the virtual switch registers the corresponding relationship between the IP address of the virtual machine and its own MAC address with the ARS, after receiving the registration of the virtual switch, record the IP address of the virtual machine and the address of the virtual switch. The corresponding relationship of the MAC address, and register the corresponding relationship and the address of the ASR with the ARS; The ASR is also used to locally query the MAC address of the communication peer and the address of the ASR to which the communication peer belongs when receiving the message sent by the virtual switch, and modify the destination MAC address of the message In order to query the MAC address of the communication peer, and encapsulate the packet into a tunnel whose destination address is the address of the ASR to which the communication peer belongs, and send it to the ASR to which the communication peer belongs through the operator network. 18. The network of claim 17, wherein: The ARS is further configured to correspondingly record the address of the home ASR when recording the correspondence between the IP address of the virtual machine registered with the virtual switch and the MAC address of the virtual switch. 19. The network according to claim 17, wherein: the virtual machine in the physical server queries the MAC address corresponding to the IP address from the ARS according to the IP address of the communication peer, including: The virtual machine in the physical server sends a MAC address resolution broadcast request, the virtual switch in the physical server converts the broadcast request into a unicast query request, and uses the unicast query request to query the communication from the ARS MAC address corresponding to the peer IP address.