CN1426169A - Method for improving route repeat liability of access server - Google Patents

Abstract

The invention relates to a method for improving the routing and forwarding reliability of an access server, in particular to a method for hot backup of a routing and forwarding module in a distributed access server. The present invention is provided with two routing and forwarding modules, configures the same virtual IP address for the above two routing and forwarding modules; the virtual media access control protocol (MAC) address corresponding to the above-mentioned virtual IP address is set for the network ports of the two routing and forwarding modules, Correspondence between the virtual MAC address and the actual MAC address of the network ports in the two routing and forwarding modules. Therefore, in the routing and forwarding service switching process of the two routing and forwarding modules, the source IP address and the source MAC address of the data packets sent by the present invention do not change, thereby realizing the transparency to the upper layer business in the routing and forwarding business switching process, ensuring This improves the continuity of routing and forwarding services, thereby improving the reliability of routing and forwarding by the access server.

Description

Method for Improving Reliability of Access Server Routing Forwarding

technical field

The invention relates to a method for improving the routing and forwarding reliability of an access server, in particular to a method for hot backup of a routing and forwarding module in a distributed access server.

Background technique

The distributed access server is a remote access access device that can provide dial-up/integrated service digital network access, dedicated line access, inter-frame cascading, and frame relay access business applications. Its structure includes routing and forwarding modules, access module etc. The routing and forwarding module is responsible for Internet Protocol (IP) packet forwarding, and transfers the uplink IP packets received by the access module to the IP core network through the uplink network port; receives the IP packets sent by the downlink network port, and forwards them to the relevant access modules. Various access modules are responsible for completing the adaptation of various IP access networks, completing user access and authentication by performing the functions of the access network itself; at the same time, stripping the uplink IP packets from the access network packets to the The routing and forwarding module packs the downlink IP packets sent by the routing and forwarding module with the access network protocol and delivers them to the user.

As can be seen from the above, both the uplink message from the user to the Internet and the downlink message from the Internet to the user need to be forwarded by the routing and forwarding module. Therefore, when the routing and forwarding module in the access server fails, if there is no other If a routing and forwarding module takes over its routing and forwarding services, all services will be interrupted. The particularity of the access service requires the equipment to have carrier-class features. It is necessary to ensure the continuity of message forwarding. If the message forwarding is interrupted, it will cause great losses to users.

However, depending on application layer protocols such as hypertext transfer protocol, file transfer protocol, and terminal network protocol, the routing and forwarding module needs to exchange messages with the peer end through the local address and the peer end address. The local address includes IP address and Media Access Control Protocol (MAC) address; the current routing protocol does not allow the same IP address to be configured in two routing and forwarding modules with different network ports in a system, because this will cause confusion in the routing table , thus causing a series of problems; in addition, for different network ports, their MAC addresses are also different. Therefore, the above problems have not been overcome at present, so when the routing and forwarding module in the access server fails, the routing and forwarding service is switched to another routing and forwarding module, and the switching process is transparent to the upper layer business, that is, the routing and forwarding module is not implemented. Hot backup of the forwarding module.

Contents of the invention

The purpose of the present invention is to provide a method for improving the routing and forwarding reliability of the access server. When the routing and forwarding module of the access server fails, the routing and forwarding service can be switched to the standby routing and forwarding module.

The purpose of the present invention is achieved like this:

(1) Two routing and forwarding modules are set, and the same virtual IP address is configured for the above two routing and forwarding modules;

(2) a virtual media access control protocol (MAC) address is set for the above-mentioned two routing and forwarding module network ports, and the link layer address corresponding to the virtual IP address is the virtual MAC address;

(3) Add the virtual IP address configured in the routing and forwarding module that needs to enter the working state to the network port, and simultaneously add the virtual MAC address to the network port of the routing and forwarding module, and the routing and forwarding module enters the working state.

The step (3) also includes the process of determining the routing forwarding module that needs to enter the working state.

The process of determining the routing forwarding module that needs to enter the working state includes:

(1) Set the priority of the routing and forwarding module: set the routing and forwarding module that needs to enter the working state as the priority;

(2) judging the priority of the routing and forwarding module, making the routing and forwarding module with priority first enter the working state;

(3) monitor the routing and forwarding module entering the working state;

(4) When the monitoring routing and forwarding module in the working state fails, another routing and forwarding module has priority and enters the working state.

The process of monitoring the routing and forwarding module in working state includes:

(1) set up the routing forwarding management module, the routing forwarding module in the working state sends the handshake message (Hello packet) to the routing forwarding management module regularly;

(2) Routing forwarding management module regularly checks whether to receive Hello packet;

(3) When the routing and forwarding management module does not receive the Hello packet sent by the routing and forwarding module in the working state within the specified time, it is considered that the routing and forwarding module is faulty.

The link-layer address corresponding to the virtual IP address is the virtual MAC address, which is realized by filling the link-layer address with the virtual MAC address through the data packet sent by the network port of the routing and forwarding module in the working state.

After the virtual MAC address is added to the network port of the routing and forwarding module, the network port also needs to actively send a data packet to complete the update of the corresponding relationship between the virtual MAC address and the specific physical device.

In the present invention, two routing and forwarding modules are set in the distributed access server, and the same virtual IP address is configured for the two routing and forwarding modules, and a virtual MAC address corresponding to the virtual IP address is established at the same time, so that the present invention can be used in both routing and forwarding modules. During the routing and forwarding service switching process of each routing and forwarding module, the source IP address and source MAC address of the data packets sent by it will not change, thus realizing the transparency of the upper layer business during the routing and forwarding service switching process and ensuring the continuity of the routing and forwarding business Reliability, thus improving the reliability of routing and forwarding of the access server. The invention solves the problem that the hot backup of the routing and forwarding modules cannot be realized because different routing and forwarding modules in the same system cannot be configured with the same IP address and the MAC addresses of different network ports are different. The present invention has been applied in the access server. When the routing and forwarding module in the working state fails for 1-3 seconds, the system detects the change of the working state of the routing and forwarding module, and notifies the standby routing and forwarding module to take over its routing and forwarding business. The switching process of the forwarding service is completely transparent to the external network, that is, the upper-layer service.

Description of drawings

Fig. 1 is the flow chart of the method for improving the routing and forwarding reliability of the access server;

FIG. 2 is a schematic diagram of the principle of the present invention applied to an access server.

Detailed ways

The method for improving the routing and forwarding reliability of the access server in the present invention improves the routing and forwarding reliability by implementing hot backup of the routing and forwarding module in the access server. The specific embodiment is described as follows in conjunction with Fig. 1:

Step 1: Set up two routing and forwarding modules in the access server;

Step 2: Configure the same virtual IP address for the above two routing and forwarding modules;

Step 3: Add the virtual IP address configured in the routing and forwarding module to the network port as needed, the process is as follows:

A. Judging the priority and working status of the routing and forwarding module: pre-set one of the routing and forwarding modules as the priority. When the routing and forwarding module with the higher priority fails and cannot work normally, the backup routing and forwarding module is considered to be the priority. class first;

B. Execute the command to configure the IP address for the routing and forwarding module with priority, and add the configured virtual IP address to the network port of the routing and forwarding module.

Under normal circumstances, add the virtual IP address configured by the routing and forwarding module with priority to the network port, so that the virtual IP address configured in the access server points to the routing and forwarding module, that is, the routing and forwarding module configured The virtual IP address is valid externally. The routing and forwarding module enters the working state and is responsible for the routing and forwarding business in the access server, which is the forwarding business of uplink and downlink data packets; the other routing and forwarding module is a backup routing and forwarding module, used when priority When the routing and forwarding module of the first level fails, it takes over its routing and forwarding business, and the virtual IP address configured by the standby routing and forwarding module is not added to the network port to avoid routing conflicts.

Step 4: Connect all the network ports of the two routing and forwarding modules to the network hub (HUB), and one of the network ports on one routing and forwarding module is physically connected to one of the network ports on the other routing and forwarding module Set a virtual media access control protocol (MAC) address for each group of network ports above, and the virtual IP address corresponds to the virtual MAC address, that is, the source address of the data packet sent by the routing and forwarding module is the configured virtual IP address , The source MAC address is a virtual MAC address.

Add the virtual MAC address to the corresponding network port of the routing and forwarding module with the priority first, so that the corresponding relationship between the virtual MAC address and the network port of the routing and forwarding module with the priority priority is valid, so that the downlink data packet can be sent to the network port with the priority priority on the corresponding network port of the routing and forwarding module.

When the external network sends a request for the corresponding relationship (ARP) between the virtual IP address and the link layer address to the virtual IP address, the routing and forwarding module in the working state responds; and when the routing and forwarding module in the working state breaks down, Another routing and forwarding module enters the working state, responds to the ARP request of the external network for the virtual IP address, and actively sends a data packet to notify the downlink data packet to be sent to the corresponding network port of the routing and forwarding module, and completes the virtual MAC address and specific physical device Correspondence update.

Step 5: The routing and forwarding module with priority first enters the working state, and establishes the routing and forwarding management module at the same time. The routing and forwarding module in the working state regularly sends a handshake message (Hello packet) to the routing and forwarding management module, and the interval time for sending the Hello packet Can be set according to actual needs;

Step 6: Access the routing and forwarding module in the server to perform normal routing and forwarding.

Step 7: The routing and forwarding management module regularly checks whether the Hello packet is received; if the Hello packet is received normally, it is considered that the routing and forwarding module is working normally, and continues to step 6 to perform routing and forwarding normally; when the routing and forwarding management module is within the specified time When the Hello packet sent by the routing and forwarding module in the working state is not received, it is considered that the routing and forwarding module is faulty, and step 8 is performed;

Step 8: Execute relevant commands to add the virtual IP address configured in the standby routing forwarding module to the network port, so that the virtual IP address configured in the access server points to the standby routing forwarding module;

Step 9: Add the virtual MAC address to the corresponding network port of the standby routing forwarding module, so that the corresponding relationship between the virtual MAC address and the network port of the standby routing forwarding module is valid, and the virtual MAC address replaces the actual MAC of the corresponding network port in the standby routing forwarding module address;

Step 10: The routing and forwarding business of the routing and forwarding module in the working state is taken over by the standby routing and forwarding module, and the standby routing and forwarding module enters the working state, and step 6 is performed to perform normal routing and forwarding.

In this way, after the standby routing forwarding module takes over the routing forwarding business, the source IP address and source MAC address of the data packets sent have not changed, and the received data packets can still be accurately sent to the corresponding network of the standby routing forwarding module. On the interface, the transparent switching from the routing forwarding module in the working state to the standby routing forwarding module is realized, which not only realizes the hot backup of the routing forwarding module, ensures the continuity of the routing forwarding business, but also improves the reliability of routing forwarding.

The method for improving the routing and forwarding reliability of the access server described in the present invention is applied to the specific implementation of the distributed access server in conjunction with FIG. 2 and is described as follows:

Set two high-speed routing forwarding boards in the distributed access server, one is the main high-speed routing forwarding board (HRB1), and the other is the standby high-speed routing forwarding board (HRB2). HRB1 and HRB2 are connected through an Ethernet switch, and HRB1 and Any two network ports of HRB2 are connected through HUB, for example, the first network port of HRB1 is connected with the first network port of HRB2, so that the data packets sent from the external network can be received by both network ports to provide hardware possible. Configure the same virtual IP address on HRB 1 and HRB2 respectively; set a virtual MAC address corresponding to the virtual IP address corresponding to the two connected network ports, and the virtual MAC address can correspond to the actual network port of HRB1 or HRB2. The source addresses of the data packets sent out by HRB1 and HRB2 are filled with the above-mentioned virtual IP address and virtual MAC address. When a data packet is sent from the outside, according to the corresponding relationship between the virtual MAC address and the corresponding network port of the corresponding high-speed routing board, the message whose destination MAC address is the virtual MAC address can be received.

When working normally, HRB1 is responsible for the routing and forwarding business of the access server, and both uplink and downlink data packets are forwarded by it. When HRB1 fails, the system management board will notify HRB2 to add the virtual IP address configured by HRB2 to the network port, and at the same time make each network port on HRB2 send data packets to the Ethernet switch, and establish a virtual MAC address and HRB2 on the Ethernet switch. The corresponding relationship between the network ports on the network, so that HRB2 takes over the routing and forwarding business of HRB1, and the whole process is completely transparent to the external network, realizing the hot backup of the high-speed routing and forwarding board. Therefore, when the present invention is applied to the access server, the reliability of routing and forwarding of the access server is improved, and the continuity of routing and forwarding services is guaranteed.

Claims (6)

1, a kind of method that improves route repeat liability of access server comprises:

(1) two Routing Forward Modules is set, is the identical virtual ip address of above-mentioned two Routing Forward Modules configuration;

(2) for above-mentioned two Routing Forward Module network interfaces virtual medium access-control protocol (MAC) address is set, virtual ip address link corresponding layer address is this virtual mac address;

(3) needs are entered the virtual ip address that disposes in the Routing Forward Module of operating state and be added on the network interface, also virtual mac address is added to simultaneously on the network interface of this Routing Forward Module, this Routing Forward Module enters operating state.

2, the method for raising route repeat liability of access server according to claim 1 is characterized in that also comprising in the described step (3): definite process that need enter the Routing Forward Module of operating state.

3, the method for raising route repeat liability of access server according to claim 2 is characterized in that the process that described definite needs enter the Routing Forward Module of operating state comprises:

(1) set Routing Forward Module priority: the Routing Forward Module that needs is entered operating state is set at priority formerly;

(2) priority of judgement Routing Forward Module makes priority Routing Forward Module formerly enter operating state;

(3) Routing Forward Module that enters operating state is monitored;

(4) monitor the Routing Forward Module that enters operating state when breaking down, then make another Routing Forward Module priority formerly, and enter operating state.

4, the method for raising route repeat liability of access server according to claim 3 is characterized in that the described process that in running order Routing Forward Module is monitored comprises:

(1) set up the routing forwarding administration module, the Routing Forward Module in running order regularly sends handshake message (Hello packet) to the routing forwarding administration module;

(2) the routing forwarding administration module is made regular check on and whether is received Hello packet;

(3) when the routing forwarding administration module is not received the Hello packet that in running order Routing Forward Module sends at the appointed time, think that then this Routing Forward Module road breaks down.

5, the method for raising route repeat liability of access server according to claim 1 is characterized in that described virtual ip address link corresponding layer address is that virtual mac address is that packet that the network interface by in running order Routing Forward Module sends is filled link layer address with virtual mac address and realized.

6, the method for raising route repeat liability of access server according to claim 1, it is characterized in that describedly virtual mac address is added on the Routing Forward Module network interface back network interface also needing initiatively to send a packet, finish virtual mac address and the specifically renewal of physical equipment corresponding relation.

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