WO2007062559A1

WO2007062559A1 - A method and gateway device for service recovery when master and slaving gateway devices switched

Info

Publication number: WO2007062559A1
Application number: PCT/CN2006/002080
Authority: WO
Inventors: Yi Xiong
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2005-12-01
Filing date: 2006-08-16
Publication date: 2007-06-07
Also published as: CN101164307A; CN100527716C; CN1980224A

Abstract

A method and a gateway device for service recovery when master and slaving gateway devices switched, the said gateway device includes a VRRP module embedding a switching notify module and a BGP module embedding a VRRP apperceiving module, and the VRRP protocol is functioned between said master and slaving gateway devices. The gateway device uses the VRRP virtual address as the source address of the BGP protocol when the BGP protocol connection between the user device and the gateway device is connected, and the new master gateway device establishes BGP protocol connection with the user device by GR manner, after the gateway devices switching the states between master and slaving, so that it is able to ensure the protocol connection is established smoothly between the user device and the new master gateway device. It can short the service interrupt time caused by switching the master and slaving states of the gateway device, and enhance the network reliability to meet the user’s demand by this method.

Description

TECHNICAL FIELD The present invention relates to the field of communications, and in particular, to a method and a gateway device for service recovery after a state switch of an active and standby gateway device.

Background technique

With the development of network technology, users have increasingly demanded network reliability. User equipment usually requires access to dual gateway devices. Virtual Router Redundancy Protocol (VRRP) is implemented between gateway devices to enable gateways. The switching of the device is transparent to the user device. In some scenarios, the user equipment is a Layer 3 device such as a router. It runs BGP with the VRJRP-enabled gateway device and exchanges routes with each other. In the prior art, in the application scenario, if the primary gateway device fails to cause the gateway device state to be switched, the user equipment removes the Border Gateway Protocol (BGP) established between the primary gateway device and the previous primary gateway device. Neighbor relationship, and then establish a BGP neighbor relationship with the new primary gateway device. There is a process in which a forwarding entry generated by the BGP protocol is deleted and then created, which will result in a long time (a few seconds, ten seconds, or even Tens of seconds of business interruption, it is difficult to meet customer requirements for network reliability.

In another existing network system, the gateway device does not use the VRRP function, and the BGP protocol connection is established between the user equipment and the dual gateway device by using the interface of the gateway device or the loopback address, and the user equipment uses the preferred technology selection of the BGP protocol itself. A gateway device acts as a service uplink. When the selected gateway device fails, the user equipment uses the convergence technology of the BGP protocol to sense its fault and selects another gateway device as the service uplink. In this prior art, when the user equipment senses that the primary gateway device is faulty and changes the forwarding entry pointing to the primary gateway device to point to the backup gateway, the service is interrupted, and when the number of forwarding entries is large, the service is interrupted. The time is still long, and it is difficult to meet the requirements of users for network reliability.

Summary of the invention

The present invention provides a method for service recovery after the state switching of the active and standby gateway devices and a corresponding gateway device, and establishes a new primary gateway device and user setting without causing service interruption. Prepare a connection between the BGP protocol.

According to an aspect of the present invention, a method for service recovery after a state switch of an active/standby gateway device includes:

When a border gateway protocol BGP connection is established between the user equipment and the gateway device, the gateway device uses the virtual redundant routing protocol VRRP virtual address as the source address of the BGP protocol.

After the primary and secondary state of the gateway device is switched, the new primary gateway device establishes a BGP connection with the user equipment by gracefully restarting the GR.

Optionally, the gateway device includes a VRRP module and a BGP module, where the user equipment includes a BGP module, and the new primary gateway device establishes a BGP connection with the user equipment in the manner of the GR.

The VRRP module in the new primary gateway device notifies the gateway device state switching message to the BGP module of the new primary gateway device;

After receiving the gateway device state switching message, the BGP module of the new primary gateway device sends a BGP connection request packet to the BGP module of the user equipment;

The BGP module of the user equipment processes the received BGP connection request message in GR mode.

Optionally, the sending, by the BGP module of the user equipment, the connection request message of the BGP protocol includes: the BGP module of the gateway device inserts a restart flag in the neighbor setup message, and initiates a protocol connection request with the user equipment.

Optionally, the method further includes:

An IBGP protocol connection is established between the gateway devices. The new primary gateway device and the previous primary gateway device have routes advertised by the user equipment. After the gateway device state is switched, the new primary gateway device establishes a BGP connection with the user equipment. The new primary gateway device forwards the traffic coming back from the bearer network to the user equipment by using the route.

Optionally, the new primary gateway device is established with the user equipment by using a GR manner.

When BGP is connected, it also includes:

The new primary gateway device re-learns from the user equipment the route that the previous primary gateway device points to the user equipment;

The new primary gateway device forwards the route to the previous primary network through the IBGP protocol. Off the device, the previous primary gateway device retains the received route and deletes the corresponding route learned directly from the user equipment according to the received route;

After the GR of the new primary gateway device and the user equipment ends, the new primary gateway device deletes all routes directed to the user equipment learned from the previous primary gateway device; and the new primary gateway device is used to the previous primary device. The gateway device advertises that the GR ends, and the previous primary gateway device deletes all routes obtained directly from the user equipment.

Optionally, the new active gateway device advertises the GR end to the previous active gateway device by extending the VRRP protocol packet.

Optionally, when the new primary gateway device establishes a BGP connection with the user equipment, the source port number different from the port number of the previous primary gateway device is used.

Optionally, the method further includes: when the primary gateway device establishes a connection with the user equipment, the primary gateway device notifies the secondary gateway device of the source port number used by the user equipment to establish a BGP neighbor by extending the VRJ P protocol.

According to another aspect of the present invention, a gateway device includes a BGP module and a VRRP module; and further includes a VRRP switch sensing module and a handover notification module;

The switching notification module is configured to advertise a gateway device state switching message to the VRRP switching sensing module;

The VRRP switch-aware module initiates a BGP connection request message to the BGP module of the user equipment according to the received gateway device state switching message, and initiates a process of establishing a BGP connection with the user equipment by using the graceful restart GR.

Optionally, the switching notification module is embedded in the VRRP module.

Optionally, the VRRP switch sensing module is embedded in the BGP module of the gateway device.

Optionally, the VRRP switch sensing module puts a restart flag in the neighbor setup message, and initiates a protocol connection request with the user equipment.

The invention establishes a BGP protocol connection between the new primary gateway device and the user equipment by using the GR mode when the state of the active and standby gateway devices is switched, so as not to cause service interruption.

In addition, since IBGP neighbors are established between the master and backup gateway devices, the slave can be resolved. The problem that the traffic returned by the network is interrupted for a long time.

In the scenario of establishing a BGP peer relationship between the user equipment and the gateway device, the service interruption time caused by the state transition of the gateway device can be effectively shortened. Based on the fast detection technology of the VRRP fault, the fault time of the end-to-end service can be made smaller than Ls, greatly better than the traditional technology of a dozen seconds, or even tens of seconds.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic diagram of a basic networking scheme adopted by an embodiment of the present invention;

Figure is a flow chart of an embodiment of the method of the present invention;

3 is a schematic diagram of a system in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a schematic diagram of a basic networking scheme according to an embodiment of the present invention. Referring to FIG. 1 , it is assumed that the gateway device 111 is the default primary gateway device, and the gateway device 112 is the backup gateway device. The signaling of the gateway device is between the gateway device 111—the switch 112—the switch 122—the gateway device 121. Hosted on the link.

The virtual redundant routing VRRP protocol is run between the gateway devices 111 and 121; the gateway devices 111, 121 and the user equipment 130 are configured to gracefully restart the GR technology.

A connection of the BGP protocol is established between the user equipment 130 and the primary gateway device 111. The gateway device 111 uses the VRRP virtual address as the source address of the BGP protocol connection; the user equipment 130 uses the VRRP virtual address as the destination address of the BGP protocol connection.

The gateway devices 111 and 121 are both provided with a VRRP module and a BGP module (not shown), and the user device 130 is provided with a BGP module (not shown).

In addition, the binding relationship between the VRRP protocol and the BGP protocol is configured on the gateway device (including the primary gateway device 111 and the backup gateway device 121). The message exchange between the specified neighbor (the user equipment 130) and the state of the gateway device is affected by the protocol. Only the master gateway device 111 can receive and send the protocol report with the user equipment 130. The backup gateway device 121 neither receives nor sends protocol packets. Therefore, the primary gateway device 111 can establish a normal protocol neighbor relationship with the user equipment 130, and the backup gateway device 121 This kind of neighbor relationship cannot be established. For the user equipment 130, it is not concerned whether the protocol neighbor is the gateway device 111 or the gateway device 121, and the neighbor address of the BGP protocol is the gateway address (VRRP virtual address), and accordingly, the next forwarding entry generated according to the BGP protocol. The hop address is also the gateway address (VRRP virtual address). The destination MAC address of the packet forwarded by the forwarding entry is the MAC address corresponding to the VRRP virtual address. According to the principle of the VRRP protocol, the VRRP protocol can only be received by the primary gateway device 111. Perform three-layer forwarding.

Of course, after the status switch of the active and standby gateway devices occurs, only the gateway device 121 that switches to the active state can establish a normal protocol neighbor relationship with the user equipment 130, and the gateway device 111 that switches to the standby state cannot establish such a neighbor. relationship.

The status switch of the active and standby gateway devices includes the following situations: A. When the gateway device 111 fails, the gateway device 121 detects that the gateway device 111 is faulty by VRRP signaling or other means, and switches to the primary gateway device; B. the gateway device 111 The priority between the gateway device 121 and the gateway device 121 is reversed, the gateway device 121 is configured to be in the preemptive mode, and the gateway device 121 actively switches to the primary gateway device. C. Modify the configuration of the gateway device 111 to leave the gateway backup group. After receiving the corresponding signaling message, the device actively switches to the primary gateway device.

After the status of the active and standby gateways is switched, the method for the service recovery after the state-switching of the active and standby gateways is enabled by the Graceful Restart (GR) mode to establish a new primary service without causing service interruption. The connection of the BGP protocol between the gateway device and the user device.

As shown in FIG. 2, an embodiment of the method of the present invention includes:

Step 201: The state of the gateway device is switched.

For example, the gateway device 111 is a previous primary gateway device, and after the gateway device status is switched, the gateway device 121 is upgraded to a new primary gateway device.

Step 202: The VRJ P module of the new primary gateway device notifies the BGP module of the new primary gateway device to switch state.

After the gateway device status is switched, the VRJ P module reports the gateway device status switch message to the BGP module.

Step 203: The BGP module of the new primary gateway device initiates a BGP connection request packet to the BGP module of the user equipment. As described above, the gateway device 121 is configured with the GR capability of the BGP. The BGP module of the gateway device 121 understands the gateway device state switching message as a GR event, and initiates a protocol connection with the user equipment. For example, the BGP module is in the OPEN (neighbor establishment). ) Put a Restart flag in the message.

Step 204: The BGP module of the user equipment performs an elegant restart according to the received connection request message.

Since the user equipment 130 is also configured with the GR capability of the BGP, and the gateway device 111 or the gateway device 121 is not distinguished from the packet, when the BGP module of the gateway device 121 initiates a new protocol connection, The user equipment 130 can trigger the GR capability of the user equipment 130, and the user equipment 130 can establish a protocol neighbor with the gateway device 121. Moreover, during the establishment of the BGP protocol, the established forwarding entries are not deleted, and the uplink service of the user equipment is not guaranteed. Interrupted.

In addition, in order to solve the problem that the traffic returned from the bearer network is interrupted for a long time, in the embodiment of the present invention, an IBGP neighbor is established between the primary gateway device and the backup gateway device. For example, the primary gateway device is the gateway device 111 and the backup gateway device is the gateway device 121. The gateway device 111 forwards the route learned from the user equipment 130 to the gateway device 121, and the next hop address is set to be unmodified, and still points to the user equipment 130, so that the gateway device 121 also has the route advertised by the user equipment 130. . After the gateway device status is switched, the gateway device 111 does not immediately delete the route learned by the BGP neighbor established by the user equipment 130, and the gateway device 121 does not immediately delete the route from the gateway device 111 to the user equipment 130, and still uses the route. The route forwards the traffic returned by the bearer network to the user equipment 130 to ensure that the service returned to the user equipment 130 is not interrupted.

During the GR process of the gateway device 121 and the user equipment 130, the gateway device 121 re-learns the route to the user equipment 130. The gateway device 121 preferably routes the information learned from the user equipment 130 and forwards it to the gateway device 111 through the IBGP neighbor. . The gateway device 111 prefers the route sent by the gateway device 121, and deletes the corresponding route learned from the user equipment 130 and the route sent by the foregoing gateway device 121. After the GR of the gateway device 121 and the user equipment 130 ends, the gateway device deletes all the routes from the gateway device 111 to the user equipment 130, and at the same time, by extending VRRP protocol packets or other protocol packets such as IBGP, the network is notified. After the device 111 GR ends, the gateway device 111 deletes all routes obtained directly from the user device 130. So far, all the routes to the user equipment 130 on the gateway device 121 are obtained directly from the BGP neighbors established with the user equipment 130, and all the routes to the user equipment 130 on the gateway device 111 are from the IBGP established with the gateway device 111. The neighbors learned. In this process, the gateway device 111 and the gateway device 121 do not actively delete the forwarding items that are directed to the user equipment 130, but use the technology of combining update and deletion, which effectively ensures that the traffic returned to the user equipment 130 is not due to the status of the gateway device. The switch was interrupted.

It can be understood that when the user is insensitive to the traffic interruption time returned by the bearer network, or other technologies such as static routing or IBGP protocol are deployed on the gateway device 111 and the gateway device 121 to guide the forwarding of the traffic returned from the bearer network, It is not necessary to deploy the IBGP protocol between the gateway device 111 and the gateway device 121.

In addition, for the GR process, the source port number of the newly established connection is generally required to be different from the previously connected port number. Otherwise, TCP may ignore or incorrectly process the new connection request, resulting in GR failure or GR recovery time becoming longer. In order to solve this problem, the primary gateway device can advertise the source port number used by the BGP neighbor established by the user equipment with the user equipment by extending the VR P protocol or other protocols such as IBGP, so that the standby gateway device becomes the new primary gateway. After the device establishes a BGP neighbor relationship with the user equipment, you can avoid using this port number as the source port number.

As shown in FIG. 3, the gateway device provided by the present invention is provided with a handover notification module 311 and a VRRP handover awareness module 321 .

The switch notification module 311 can be embedded in the VRRP module 310 of the gateway device, and the VRRP switch perception module 321 can be embedded in the BGP module 320 of the gateway device.

The handover notification module 311 is configured to notify the VRRP handover awareness module 321 of the gateway device status switching message.

The VRRP switch sensing module 321 initiates a BGP connection request message to the BGP module 400 of the user equipment according to the received gateway device state switching message.

In an embodiment, the VRRP switch sensing module 321 of the gateway device understands the gateway device state switching message as a GR event, and initiates a protocol connection with the user equipment. For example, put a Restart in the OPEN (Neighbor Establishment) message. mark. The BGP module 400 of the user equipment performs graceful restart of the GR according to the received BGP protocol connection request message.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope of the present invention. All should be covered by the scope of the present invention.

Claims

Rights request

A method for service recovery after a state switch of an active/standby gateway device, which is characterized by:

When a border gateway protocol BGP connection is established between the user equipment and the gateway device, the gateway device uses the virtual redundant routing protocol VRJ P virtual address as the source address of the BGP protocol;

The method of claim 1, wherein the gateway device comprises a VRRP module and a BGP module, the user equipment comprises a BGP module, and the new primary gateway device adopts a GR mode and a user equipment. Establishing a BGP connection specifically includes:

The method according to claim 2, wherein the sending the BGP connection request message to the BGP module of the user equipment comprises: the BGP module of the gateway device placing a restart flag in the neighbor setup message , initiate a protocol connection request with the user equipment.

4. The method according to claim 1, further comprising:

The method according to claim 4, wherein when the new primary gateway device establishes a BGP connection with the user equipment in the manner of the GR, the method further includes:

The method according to claim 5, wherein the new active gateway device advertises the GR end to the previous active gateway device by extending the VRJRP protocol message.

The method according to claim 1, wherein when the new primary gateway device establishes a BGP connection with the user equipment, the source port number different from the port number of the previous primary gateway device is used.

The method according to claim 7, further comprising: when the primary gateway device establishes a connection with the user equipment, the primary gateway device notifies the secondary gateway device that the BGP neighbor relationship is established with the user equipment by using the extended VRRP protocol. Source port number.

A gateway device, including a BGP module and a VRRP module, further comprising a VR P switch sensing module and a switch notification module;

10. The gateway device according to claim 9, wherein the switching notification module is embedded in the VRRP module.

The gateway device according to claim 9, wherein the VRRP switch sensing module is embedded in a BGP module of the gateway device.

The gateway device according to any one of claims 9 to 11, wherein the VRRP handover aware module puts a restart flag in the neighbor setup message, and initiates a protocol connection request with the user equipment.