WO2008011818A1

WO2008011818A1 - Method of realizing hierarchy-virtual private lan service and network system

Info

Publication number: WO2008011818A1
Application number: PCT/CN2007/070200
Authority: WO
Inventors: Guoyi Chen
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-07-14
Filing date: 2007-06-28
Publication date: 2008-01-31
Also published as: CN101106507A; CN101106507B

Abstract

A method of realizing Hierarchy-Virtual Private LAN Service and network system are disclosed to decrease the waste of the resource in the process of message-forwarding and improve the bandwidth usage. The method of realizing Hierarchy-Virtual Private LAN Service includes the following steps: the Virtual Private LAN Service network is divided in accordance with the autonomous system; inside the service Provider Edge routers among the autonomous systems, network connections are established; and aimed at the each case of the Virtual Private LAN Service, the pseudo wires among the service Provider Edge routers are established; to each case of the Virtual Private LAN Service, one pseudo wire is established among the communicating autonomous systems; and the Customer Edge routers use the established pseudo wires to communicate with each other. It can effectively improve the efficiency of route distribution.

Description

Method and network system for realizing layered virtual private local area network service The application is submitted to the Chinese Patent Office on July 14, 2006, the application number is 200610099413.5, and the invention name is "a method for realizing layered virtual private local area network service" Priority of the Chinese Patent Application, the entire contents of which is incorporated herein by reference.

Technical field

The present invention relates to the field of communications, and in particular, to a method and network system for implementing a layered virtual private local area network service.

Background technique

With the continuous development of the Internet Protocol (IP) network, the richness, security, and flexibility of network services have become an important way for operators to improve their profitability. At present, many companies have more and more internal networks and more and more areas; they may be distributed in different urban areas in a city, or in different cities or even all over the world; The network is connected, and the network operator is required to provide network connectivity. This is because a company cannot build such a large network by itself.

For a long time in the past, enterprises have completed the connection between various networks by leasing leased lines to telecom operators. However, these methods have problems such as large investment, long construction period, and poor scalability. The MPLS L2VPN (Multiple Protocol Label Switched L2 Virtual Private Network) provides a new solution that not only provides users with various interconnection services but also guarantees the network. Safe, but also provide quality of service (QOS, Quality-of-Service) guarantee.

Virtual Private LAN Service (VPLS) is a point-to-multipoint application architecture of MPLS L2VPN. It borrows the idea of LAN (Local Area Network) and builds a virtual LAN service using IP/MPLS technology. Provides transparent Ethernet data transmission. From the user's point of view, the operator connects the network around itself like a large switch. The VPLS technology solves the limitation of the traditional switch virtual local area network (VLAN) ID. For example: The switch can only provide 4096 VLAN IDs, and each user needs at least one VLAN ID. These restrictions are applicable to the network. Both scalability and large-scale deployments can cause problems, and the Signalling Transfer Point (STP) protocol needs to be run to prevent network loops and increase the burden on the network. Figure 1 shows the typical network structure of VPLS.

There are two schemes for implementing VPLS, namely: Martini VPLS and Kompella VPLS. The operation of the data forwarding layer is the same for both schemes, but the operation at the control level is different.

The difference between Martini VPLS and Kompella VPLS is mainly reflected in the signaling and discovery mechanism. Martini VPLS uses the Label Distribution Protocol (LDP) as the signaling for establishing the virtual link (PW, Pseudo Wire). The automatic discovery mechanism is not defined. , need to be manually configured to complete the discovery of the service provider edge (PE, Provider Edge) router, so there is scalability problem; Kompella VPLS uses Border Gateway Protocol (BGP) as the signaling to establish PW, automatic discovery mechanism Also done with BGP.

A method for implementing a layered virtual private LAN service in the prior art is a Martini VPLS Hierarchy-Virtual Private LAN Service (H-VPLS) scheme, as shown in FIG. 1: All PE routers 10 In a network plane, all PE routers 10 need to establish a full connection, and all user edge (CE, Customer Edge) routers 20 are also directly connected to the PE router 10; or as shown in FIG. 2, the PE router 10 in the backbone network The number is reduced. Some CE routers 20 are connected to the User-facing Provider Edge (UPE) router 12; with this improvement, the full connectivity and signaling overhead of the PE 10 in the backbone network is reduced a lot. For the network core Provider Edge (NPE) router 11, only the other NPE routers 11 and the local UPE routers 12 need to be concerned. For the UPE router 12, only the CEs directly connected to them are concerned. Router 20 and NPE router 11. The forwarding plane of the VPLS is forwarded through the destination medium access control (MAC) address. For the packets of the unknown destination MAC address, the data packet needs to be broadcast to all interfaces. It is called the "first packet". At the forwarding level, for the "first packet", the PE router 10 in the flat network structure shown in FIG. 1 needs to complete forwarding to all CE routers 20 and other PE routers 10, in the network structure shown in FIG. It only needs to be forwarded to a small number of CE routers 20, UPE routers 12 and other NPE routers 11, so that the impact of the "first packet" on the NPE router 11 can be reduced.

However, the Martini H-VPLS solution can only solve the problem of an autonomous system because it is based on LDP, Interior Gateway Protocol (IGP), and PWE3 (Pseudowire Emulation Edge to Edge). Cannot be deployed across autonomous systems; Because there is no automatic discovery mechanism, you need to manually configure it. This requires a lot of manual configuration, which is very unfavorable for maintenance management. Therefore, Martini H-VPLS is not suitable for operators to deploy VPLS on a large scale.

In order to solve the above drawbacks of the prior art, another method for implementing the layered virtual private LAN service in the prior art is the H-VPLS scheme of Kompella VPLS: The scheme uses a route reflector to reduce a large number of PEs. The router has a full mesh problem. In an autonomous system, all PE routers and the route reflector establish an internal border gateway protocol (IBGP) connection by configuring a route reflector. At the same time, the outbound route filter (ORF) is used to limit the distribution of unnecessary routes, and some PWs are reduced. For the route distribution between autonomous systems, constraint-based route specifier filtering (RTF, Route Target Filter) is adopted. The mechanism to limit the distribution of routing information is not required; due to the inherent advantages of BGP, cross-domain problems can be well solved.

However, the H-VPLS solution of Kompella VPLS only solves the problem of full mesh of a large number of PE routers, and can limit the distribution of unnecessary routing information. It does not solve the problem that each PE router maintains a large number of PWs and "first packet". The problem of replication; that is, each PE router needs to maintain almost all PWs, and the "first packet" needs to be copied to all local CE router interfaces and PW interfaces.

In addition, for the case where the virtual private network site (VPN site) is deployed in different autonomous systems (ASs), the packets broadcasted by the entire network in an AS need to pass through each PW belonging to the VPLS instance. Other ASs send, these PWs may all be mapped to the same physical link, so there are a large number of "repetitive messages, transmitted between ASs, occupying a lot of inter-domain path bandwidth, that is, the communication autonomous system There will be multiple virtual links between them, causing "repetitive messages" to be sent multiple times between autonomous systems.

Summary of the invention

The embodiments of the present invention provide a method and a network system for implementing a layered virtual private local area network service, which can reduce resource waste and improve bandwidth utilization in the file forwarding process.

Embodiments of the present invention provide a method for implementing a layered virtual private local area network service, including the steps of: dividing a virtual private local area network service network according to an autonomous system; establishing a network connection between service provider edge routers in each autonomous system, and for each Virtual private LAN service instances establish virtual links between service provider edge routers; between each autonomous system that communicates with each virtual private office The domain network service instance establishes a virtual link; the user edge router uses the established virtual link for communication. The embodiment of the invention provides a network system for implementing a hierarchical virtual private local area network service, where the virtual private local area network service network is divided according to an autonomous system, including:

a service provider edge router, configured to establish a network connection within each autonomous system, and establish a virtual link for each virtual private local area network service instance;

An autonomous system border router for establishing a virtual link for each virtual private area network service instance between autonomous systems that communicate;

User edge router, used to communicate with the established virtual link.

The embodiment of the present invention reduces the virtual link by establishing only a virtual link between the service provider edge routers in the autonomous system and establishing only one virtual link between the autonomous systems for each virtual private local area network service instance. The complexity of the establishment, and because only one virtual link is established, the packets between the autonomous systems are not repeatedly sent, which also improves the bandwidth utilization between the autonomous systems.

DRAWINGS

1 is a typical network structure diagram of a prior art VPLS;

2 is a schematic diagram of a prior art network structure;

3 is a network structure diagram of an embodiment of the present invention;

Figure 4 is a flow chart of the first embodiment of the present invention;

Figure 5 is a flow chart of a second embodiment of the present invention;

Figure 6 is a flow chart of a third embodiment of the present invention;

7 is a schematic structural diagram of an ASBR in a network system structure according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a PE router in a network system structure according to an embodiment of the present invention.

detailed description

The specific embodiments of the embodiments of the present invention are described below in conjunction with the accompanying drawings.

The embodiments of the present invention provide a method for implementing a layered virtual private local area network service, which is used to reduce resource waste and improve bandwidth utilization in a message forwarding process.

The embodiment of the present invention can implement H-VPLS by using BGP extension.

VPLS delivers data traffic between sites in each VPN by establishing a fully-connected PW between PE routers on the IP/MPLS backbone network. After the PW between PEs is completed, the ingress PE (Ingress) The router receives the data packet and queries the Forwarding Data Base (FDB) table according to the destination MAC address of the packet. If the corresponding entry is found, the data packet is forwarded to the corresponding outgoing interface PE according to the entry. Egress PE) router; if If the unicast or multicast is unknown, the data packet is forwarded to all interfaces of the VPLS instance, including the PW interface. The source MAC address learning is performed at the same time. The Egress PE router receives the data packet sent from the PW, and the corresponding VPLS instance. If the corresponding interface is found, the corresponding interface is forwarded to the corresponding interface. If the corresponding interface is not found, the VPLS instance is broadcast to all non-PW interfaces and the source MAC address is learned. After receiving the packet, the CE router forwards the packet forwarding process according to the forwarding process described above, and learns the source MAC address. After learning the MAC address, the subsequent data traffic is learned. The MAC address is forwarded as if it were a large switch. At the same time, the VPLS also provides the MAC address aging function. If a MAC address entry is not accessed within a certain period of time, the MAC address entry will be deleted.

As shown in FIG. 3, it is a structural diagram of a network system for implementing a layered virtual private local area network service according to an embodiment of the present invention. The VPLS network is divided into the first AS 31, the second AS 32, and the third AS 33 according to the AS (Autonomous System); the PE router is classified into an NPE router or a UPE router, an NPE router, or a UPE according to the network level of the AS. The router establishes a network connection in each autonomous system and establishes a virtual link for each VPLS instance. An autonomous system border router (ASBR) is used for each virtual private local area network between the autonomous systems that perform communication. The service instance establishes a virtual link; the CE router uses the established virtual link for communication.

In FIG. 3, the first AS 31 is a first-level network, and the second AS 32 and the third AS 33 are second-level networks. The first ASBR 301 is an ASBR connected to the first AS 31 in the second AS 32. The second ASBR 302 is the ASBR connected to the second AS 32 in the first AS 31; likewise, the third ASBR 303 is the ASBR connected to the third AS 32 in the first AS 31, and the fourth ASBR 304 is the third AS 33 The ASBR connected to the first AS 31. Suppose there are two VPNs, VPN 1 and VPN 2, and their sites are distributed among the above three ASs, among which the first CE router 201, the third CE router 203, the fourth CE router 204, the fifth CE router 205, and the seventh CE Router 207, ninth CE router 209, eleventh CE router 211 belong to VPN1, wherein second CE router 202, sixth CE router 206, eighth CE router 208, tenth CE router 210, twelfth CE router 212, The thirteenth CE router 213 belongs to VPN 2.

In the following, a detailed description of a method for implementing a layered virtual private local area network service according to an embodiment of the present invention is provided. Description:

Referring to FIG. 4, the first embodiment of the present invention includes the following steps:

D1) division;

The VPLS network is divided into autonomous systems.

D2) establishing a network connection;

Among them, a network connection is established between PE routers in each autonomous system.

D3) establishing a virtual link between the autonomous system and the autonomous system;

A virtual link between the PE routers is established for each VPLS instance in the autonomous system, and a virtual link is established for each VPLS instance between the autonomous systems that communicate with each other.

D4) Communicate.

The CE router uses the established virtual link for communication.

Referring to FIG. 5, a second embodiment of the present invention includes the following steps:

D1) division;

The VPLS network is divided into ASs.

D2) establishing a network connection;

This step more specifically includes:

P1) Create network layer reachability information;

The first ASBR creates network layer reachability information.

The second ASBR creates network layer reachability information.

P2) allocating a label block;

The first ASBR allocates a label block according to the created network layer reachability information.

The second ASBR allocates a label block according to the created network layer reachability information.

P3) send;

The first ASBR sends the network layer reachability information and the label block to the second ASBR. The second ASBR sends the network layer reachability information and the label block to the first ASBR. P4) selecting a label block;

The second ASBR selects the corresponding label block as the multi-association of sending data to the first ASBR. Negotiate label exchange labels.

The first ASBR selects a corresponding label block as a multi-protocol label switching label that sends data to the second ASBR.

P5) receiving routing information;

The first ASBR receives the routing information sent by the second ASBR, and the second ASBR receives the routing information sent by the first ASBR.

P6) setting community attributes;

The BGP community attribute NO—ADVERTISE is set, so that the received route is no longer sent to any other neighbors.

D4) Communicate.

The CE router uses the established virtual link for communication.

The second embodiment of the present invention provides an implementation step of establishing only one virtual link for each VPLS instance in the autonomous system.

Please refer to FIG. 6. The third embodiment of the present invention includes the following steps:

S1) division;

The VPLS network is divided into autonomous systems.

52) establishing a network connection;

53) Establish an internal virtual link;

A virtual link between PE routers is established for each VPLS instance in the AS.

54) Create network layer reachability information;

S5) allocating a label block;

S6) sending;

The network layer reachability information and the label block are sent to the second ASBR.

S7) selecting a label block;

The second ASBR selects a corresponding label block as a multi-protocol label switching label for transmitting data to the first ASBR.

S8) receiving routing information;

The ASBR receives routing information. S9) setting a community attribute;

S10) the packet is sent to the UPE router;

S11) query instance;

The UPE router finds the VPLS instance to which it belongs based on the interface connected to the CE router.

512) check the table;

The FDB table is queried according to the VPLS instance.

513) determining whether the entry exists in the table, and if yes, proceeding to step S14), if not, proceeding to step S15);

514) Send the packet to the specified interface according to the entry;

515) broadcast;

The message is broadcast to all interfaces in the instance.

The interface that correctly receives the packet is called the correct receiver.

S16) performing address learning;

The address learning includes receiving feedback from the correct recipient; recording the communication path with the correct recipient and storing it in the FDB table.

In order to ensure that the FDB table is not too large, it needs to be cleaned up, that is, some entries that have not been used for a long time can be set. The threshold time can be set before the system is run. When the address learning is completed, the FDB table is searched. If the entry is not used, the entry is aged. It can be understood that the retrieval of the FDB table does not necessarily need to be performed after the address learning is completed, or at other times.

S17) adding a label;

S18) encapsulating the message;

S19) The ASBR forwards the packet to the receiver.

S20) The recipient responds with a message.

As can be seen from the above, the third embodiment of the present invention mainly increases the address learning and the steps of aging the entries that are not used for a long period of time compared with the first embodiment and the second embodiment.

In addition, it should be noted that those skilled in the art can understand that the method in the foregoing embodiment is implemented. All or part of the steps may be completed by a program instruction related hardware, and the program may be stored in a computer readable storage medium, such as: ROM/RAM, disk, CD, etc. . A detailed description:

In the network system for implementing the layered virtual private local area network service, as shown in FIG. 7, the ASBR includes at least a receiving unit 71 and a setting unit 72, and may further include an information generating unit 73, a sending unit 74, a selecting unit 75, and Packaging unit 76; wherein:

The information generating unit 73 creates network layer reachability information (NLRI) according to the VPLS service instance and divides the packet into the west;

The message encapsulating unit 76 adds the allocated label to the packet and encapsulates it into a multi-protocol label exchange message;

The sending unit 74 sends the NLRI and the label block to the ASBR that communicates with it;

Receiving unit 71 receives routing information sent by the ASBR with which it communicates;

The setting unit 72 sets the community attribute of the edge gateway protocol;

The selecting unit 75 selects a corresponding tag from the tag blocks in the routing information according to its own identifier as a multi-protocol label switching tag that transmits data to the ASBR with which it communicates.

As shown in FIG. 8, the PE router includes a first searching unit 81, a second searching unit 82, a forwarding unit 83, and an address learning unit 84, where:

The first searching unit 81 queries the VPLS service instance to which the NPE router belongs.

The second searching unit 82 performs forwarding of the database table lookup in the instance according to the address carried in the packet;

The message forwarding unit 83 is configured to: when the second search unit finds the corresponding entry, forward the packet to the interface specified by the entry; when the second search unit does not find the corresponding entry, it will report The text is broadcast to all interfaces in the instance;

The address learning unit 84 is configured to perform address learning when the second search unit does not find the corresponding entry.

The address learning unit 84 includes at least a receiving subunit and a recording subunit, and may further include a processing subunit, and a preset subunit. The receiving subunit receives the feedback information of the correct receiving party; The subunit records the communication path with the correct receiver and stores it in the forwarding database table. The preset subunit sets the aging threshold time. The processing subunit aging the forwarding database entries that are not used after the aging threshold time.

In conjunction with the network structure of Figure 3, the implementation process of establishing only one virtual link for each VPLS instance is described in detail as follows:

The first ASBR 301 has a VPLS instance of the autonomous system. In FIG. 3, the first ASBR 301 has VPLS 1 and VPLS 2. The first ASBR 301 creates two NLRIs according to the two VPLSs, and allocates two different ACLs. The label block, the next hop is the first ASBR 301, and then the two NLRIs are sent to the second ASBR 302. After receiving the two NLRIs, the second ASBR 302 is based on its own VPLS edge device identifier (VE ID, The Vpls Edge Device Identifier selects an appropriate label from the label block as the MPLS label for the second ASBR 302 to send data to the first ASBR 301. Similarly, the second ASBR 302 also creates two NLRIs, and respectively allocates one label block. The next hop is the second ASBR 302, and then the two NLRIs are sent to the first ASBR 301. After receiving the two NLRIs, the first ASBR 301 also selects the appropriate label according to its own VE ID as the second. The ASBR 302 sends the MPLS label of the data; the same is true for the label distribution process between the third ASBR 303 and the fourth ASBR 304; after receiving these routes, these ASBRs cannot be sent to any other neighbors (through the BGP community). NO- ADVERTISE property can be easily done), so that between the ASBR, for each VPLS instance, only one virtual link.

In addition, the communication between the CE routers using the established virtual link can be as follows:

I. Assume that the sender CE router and the receiver CE router are in an AS. The communication process is as follows:

1. Referring to FIG. 3, the first CE router 201 encapsulates the MAC address of the second CE router 202 on the packet to be sent to the second CE router 202 as the destination MAC address, and sends it to the second UPE router 122, the second UPE router. The VPLS instance is found according to the interface connected to the first CE router 201. VPLS 1 searches for the FDB table in the VPLS instance according to the destination MAC address. If the related entry is found, the data is forwarded according to the entry. The interface specified by this entry; if it is the first packet, there is usually no related entry in VPLS 1. In this case, the packet needs to be broadcast to all interfaces in VPLS 1, including the PW interface. The packets sent by the PW are tagged with two layers. The inner layer is the private network label and the outer layer is the tunnel label. The source MAC address is learned at the same time.

2. After the data packet arrives at the first ASBR 301, the first ASBR 301 first determines which VPLS instance the data belongs to according to the inner label of the data packet, that is, which VPN; and then performs the destination MAC address lookup in the FDB table of the associated VPLS. If the related entry is found, the data is forwarded to the outbound interface of the entry. Similarly, if it is the first packet, there is usually no related FDB entry, so the data needs to be sent to the VPLS 1 instance. In the case of the first scenario, the second CE router 202 is directly connected to the first ASBR 301. Therefore, when the first ASBR 301 broadcasts to the local interface, the first ASBR 301 is broadcasted to the local interface. The data packet is sent to the second CE router 202;

After receiving the data packet, the second CE router 202 sends a response packet to the first CE router 201, and the response packet uses the MAC address of the first CE router 201 as the destination MAC address, and sends the data packet to the first ASBR 301; The first ASBR 301 determines the VPLS according to the interface connected to the second CE router 202, and then performs the destination MAC address lookup in the FDB table in the VPLS 1. Since the first ASBR 301 has already performed MAC learning, it should be The FDB entry can be found. The outbound interface corresponding to the entry is the virtual link interface of the first ASBR 301 to the second UPE router 122. At this time, the first ASBR 301 is allocated to the first ASBR by the second UPE router 122. The label of the 301 is used as the inner label of the label stack, and then the tunnel label between the first ASBR 301 and the second UPE router 122 is encapsulated into an MPLS packet and sent to the second UPE router 122 to learn the source MAC address. After receiving the MPLS packet sent by the first ASBR 301, the second UPE router 122 finds the corresponding VPLS instance according to the inner label: VPLS 1, in the FDB of VPLS 1. The destination MAC address is searched. Since the second UPE router 122 has learned the source MAC address, the corresponding FDB entry should be found. The outbound interface corresponding to the entry is the interface connected to the first CE router 201. Sending to the first CE router 201, the MAC learning is also performed; thus, the bidirectional path between the first CE router 201 and the second CE router 202 is opened, and the first CE router 201 and the second CE router 202 are connected. Data is forwarded on the same switch as the two interfaces in the same VLAN.

2. Assuming that the sender CE router and the receiver CE router are not within one AS, the communication process is as follows: 1. Referring to FIG. 3, the first packet sent by the first CE router 201 to the third CE router 203 also needs to undergo the communication process in the first case, and the first ASBR 301 is in the second ASBR 302. Before the packet is sent, the label allocated to the first ASBR 301 by the second ASBR 302 in the VPLS 1 is encapsulated into an MPLS packet and then sent to the second ASBR 302. The second ASBR 302 determines the VPLS to which the label belongs. It is VPLS 1; the second ASBR 302 performs MAC address lookup in the FDB table of VPLS 1. If the related entry is found, the data is forwarded to the corresponding interface; likewise, if it is the first packet, there is usually no related table. The second ASBR 302 broadcasts the data packet to all the local interfaces and the PW interface in the VPLS 1, and performs source MAC address learning at the same time;

2. Since the third CE router 203 is connected to the second ASBR 302, after receiving the data packet, the third CE router 203 performs a data packet response, and the responding data packet uses the MAC address of the first CE router 201 as the destination MAC. After being received by the second ASBR 302, the second ASBR 302 determines the VPLS to which it belongs according to the interface connected to the third CE router 203, here is VPLS 1; the second ASBR 302 performs MAC address lookup in VPLS 1, due to The second ASBR 302 has previously learned the source MAC address. The second ASBR 302 can find the corresponding entry, and the outbound interface corresponds to the PW of the second ASBR 302 to the first ASBR 301 according to the found entry. The first ASBR 301 is encapsulated with the label allocated by the first ASBR 301 for the second ASBR 302, and then sent to the first ASBR 301. After receiving the MPLS packet, the first ASBR 301 determines the VPLS to which the VPLS belongs according to the label: VPLS 1, An ASBR 301 continues to perform MAC address lookup in VPLS 1. After the related entry is found, the outbound interface corresponding to the entry is the PW between the first ASBR 301 and the second UPE router 122, and subsequent The forwarding operation is the same as the communication process in the first case described above; thus the first CE router 201 and the second CE router 203 can perform normal communication.

3. It can be understood that the foregoing second case can be further extended to the fact that the communication between the sender CE router and the receiver CE router passes through multiple ASs, and the communication process is as follows:

Referring to FIG. 3, after the first packet of the first CE router 201 to the fifth CE router 205 reaches the second ASBR 302, the second ASBR 302 broadcasts in the VPLS 1 of the first AS 31, and the first packet is The packet encapsulates the two-layer label and sends it to the third ASBR 303. The third ASBR 303 first determines the VPLS to which it belongs according to the inner label: VPLS 1, and then performs FDB table lookup; if no related entry is found, the third ASBR 303 All local interfaces of VPLS 1 and other autonomy The PW interface between the ASBRs directly connected to the system broadcasts the source MAC address learning. The data is encapsulated on the label of the fourth ASBR 304 for the VPLS 1 to the third ASBR 303, and sent to the fourth ASBR 304. The fourth ASBR The subsequent operations of the 304 are the same as the second ASBR 302 received by the first ASBR 301 in the first case communication process; the final message arrives at the fifth CE router 205, and the PE router and the ASBR along the way source. The MAC address is learned such that the data path between the first CE router 201 and the fifth CE router 205 is formed.

After receiving the routing information by the border routers of the autonomous systems, the community attribute of the edge gateway protocol is set to prevent the received routing information from being forwarded to other neighbors to reduce the waste of resources.

In the embodiment of the present invention, the address learning function can be used to record the forwarding path information of the unknown address. In the process of forwarding the packet, only the first packet packet needs to be broadcasted, and then the packet can be directly forwarded according to the entry, thereby reducing Repeated packet transmission improves the efficiency of packet forwarding.

The foregoing description of the method for implementing the layered virtual private local area network service provided by the present invention is only for helping to understand the method of the present invention and its core idea; meanwhile, for those skilled in the art, according to the present invention The present invention is not limited by the scope of the present invention.

Claims

Rights request

A method for implementing a layered virtual private local area network service, comprising the steps of: dividing a virtual private local area network service network according to an autonomous system;

Establishing a network connection between service provider edge routers within each autonomous system, and establishing a virtual link between service provider edge routers for each virtual private local area network service instance;

Establishing a virtual link for each virtual private LAN service instance between the autonomous systems that communicate;

The user edge router communicates using the established virtual link.

2. The method for implementing a layered virtual private area network service according to claim 1, wherein the step of establishing a virtual link for each virtual private area network service instance between the autonomous systems that perform communication comprises:

In the first autonomous system and the second autonomous system that perform communication, the first autonomous system border router and the second autonomous system border router respectively create network layer reachability information according to the virtual private local area network service instance and allocate the label block;

The first autonomous system border router sends the network layer reachability information and the label block to the second autonomous system border router;

The second autonomous system border router selects a corresponding label from the label block according to its own identifier as a multi-protocol label switching label for transmitting data to the first autonomous system border router;

The first autonomous system border router and the second autonomous system border router respectively receive the routing information sent by the other party, and set the community attribute of the edge gateway protocol so that the received routing information is no longer forwarded to other neighbors.

The method for implementing the hierarchical virtual private local area network service according to claim 2, wherein the step of the user edge router communicating by using the established virtual link includes:

The first user edge router sends the message to the user side service provider edge router; the user side service provider edge router forwards the message to the autonomous system border router; the autonomous system border router forwards the message to the second User edge router;

The second user edge router responds to the first user edge router with a message.

The method for implementing a layered virtual private local area network service according to claim 3, wherein the step of forwarding the message by the autonomous system border router to the second user edge router Includes:

The autonomous system border router adds a label allocated by the second autonomous system border router to the autonomous system border router in the virtual private local area network service instance, encapsulates the packet into a multi-protocol label switching message, and forwards the packet to the second autonomous system boundary. router.

The method for implementing the layered virtual private area network service according to claim 3, wherein the step of forwarding the message by the user side service provider edge router to the autonomous system border router comprises:

The user-side service provider edge router queries the virtual private local area network service instance; forwards the database table in the instance according to the address carried in the packet, and if the corresponding entry is found, the packet is forwarded to the specified by the entry. If the corresponding entry is not found, the packet is broadcast to all interfaces in the instance, and address learning is performed.

6. The method for implementing a layered virtual private local area network service according to claim 5, wherein the address learning is performed according to the following steps:

Receiving feedback information sent by the interface that correctly received the packet;

The communication path with the interface that received the message correctly is recorded and stored in the forwarding database table.

The method for implementing a layered virtual private local area network service according to claim 6, wherein the storing the forwarding database table further comprises the step of: aging the forwarding database entry that is not used after the aging threshold time.

8. The method for implementing a layered virtual private local area network service according to claim 7, wherein the storing before the forwarding of the database table further comprises the step of: setting an aging threshold time.

The method for implementing a layered virtual private local area network service according to claim 1, wherein the network connection is a full mesh connection or a route reflector connection.

A network system for implementing a layered virtual private area network service, wherein the virtual private area network service network is divided according to an autonomous system, including:

User edge router, used to communicate with the established virtual link.

11. The network system for implementing a layered virtual private area network service according to claim 10, wherein the autonomous system border router comprises:

An information generating unit, configured to create network layer reachability information according to a virtual private local area network service instance and allocate a label block;

a sending unit, configured to send network layer reachability information created by the information generating unit and the allocated label block to an autonomous system border router that communicates with the same;

a selecting unit, configured to select a corresponding label from the label block according to its own identifier, as a multi-protocol label switching label for transmitting data to an autonomous system border router that communicates with the same;

a receiving unit, configured to receive routing information sent by an autonomous system border router that communicates with the setting unit, and a setting unit, configured to set a community attribute of the edge gateway protocol.

The network system for implementing the layered virtual private local area network service according to claim 11, further comprising:

a message encapsulating unit, configured to add a multi-protocol label switching label selected by the selecting unit to a message used for communication, and encapsulate the packet into a multi-protocol label switching message, and send the message to the communication unit through the sending unit. Autonomous system border router.

13. The network system for implementing a layered virtual private area network service according to claim 10, wherein the service provider edge router comprises:

a first searching unit, configured to query a virtual private local area network service instance to which the service provider edge router belongs;

a second searching unit, configured to perform a forwarding database table lookup in the instance according to an address carried in a message used for communication;

a packet forwarding unit, configured to: when the second search unit finds the corresponding entry, forward the packet to an interface specified by the entry; when the second search unit does not find the corresponding entry, The message is broadcast to all interfaces in the instance;

The address learning unit is configured to perform address learning when the second search unit does not find the corresponding entry.

The network system for implementing the layered virtual private local area network service according to claim 13, wherein the address learning unit comprises:

a receiving subunit, configured to receive feedback information sent by an interface that correctly receives the packet; And a recording subunit, configured to record, according to the feedback information received by the receiving subunit, a communication path with an interface that correctly receives the message and store the data in a forwarding database table.

The network system for implementing the layered virtual private area network service according to claim 14, wherein the address learning unit further comprises:

The processing sub-unit is used to perform aging processing on forwarding database entries that are not used after the aging threshold time.

The network system for implementing the layered virtual private local area network service according to claim 15, wherein the address learning unit further comprises:

Preset subunit, used to set the aging threshold time.

The network system for implementing a layered virtual private local area network service according to claim 10, wherein the user edge router comprises:

A message sending unit, configured to send the message to the service provider edge router.

18. The network system for implementing a layered virtual private area network service according to claim 10, wherein the network connection is a full mesh connection or is connected by a route reflector.