CN107070787B

CN107070787B - Default route revocation method and device

Info

Publication number: CN107070787B
Application number: CN201710279318.1A
Authority: CN
Inventors: 余清炎
Original assignee: Hangzhou H3C Technologies Co Ltd
Current assignee: Hangzhou H3C Technologies Co Ltd
Priority date: 2017-04-25
Filing date: 2017-04-25
Publication date: 2020-10-27
Anticipated expiration: 2037-04-25
Also published as: CN107070787A

Abstract

The invention discloses a method and a device for withdrawing default route. The method is applied to equipment for operating a Border Gateway Protocol (BGP), and comprises the following steps: when determining that the equipment has default route revocation information to be sent, carrying the default route revocation information in a first BGP message sent to a target BGP neighbor; the target BGP neighbor is an IBGP neighbor or an EBGP neighbor; and when determining that the default route revocation information is sent to all target BGP neighbors of the equipment, locally deleting the default route indicated by the default route revocation information. The technical scheme of the invention solves the problem of overlong service interruption time caused by the late sending of the default route withdrawal message.

Description

Default route revocation method and device

Technical Field

The present invention relates to the field of network communication technologies, and in particular, to a method and an apparatus for revoking a default route.

Background

BGP (Border Gateway Protocol) is a dynamic routing Protocol that can be used both between different ASs (Autonomous systems) and within the same AS. BGP running inside ASs is called IBGP, and BGP running between ASs is called EBGP.

In a conventional enterprise campus network or data center network, the network is typically divided into an access layer, a convergence layer, and a core layer. With the continuous expansion and development of networks, in order to make the convergence performance of the network from the abnormal state to the normal state better, the BGP protocol is usually run directly on each layer, and each layer is divided into one or more AS areas.

Fig. 1 is a simplified networking diagram of a conventional data center network. As shown in fig. 1, CORE-ROUTER is a CORE layer device, LSW-1 and LSW-2 are convergence layer devices, and VM-SERVER is an access layer device. EBGP neighbors are established between the CORE-ROUTER and the LSW-1 and the LSW-2 respectively, and the LSW-1 and the LSW-2 and the VM-SERVER respectively. The CORE-ROUTER sends the default route and the detailed route to LSW-1 and LSW-2, and LSW-1 and LSW-2 only send one default route to VM-SERVER. Here, the default route is a special static route, which refers to a selection that the router can make when there is no matching entry in the routing table with the destination address. If the default route does not exist, the packet of which the destination address does not match the table entry in the routing table is discarded, and if the default route exists, the packet of which the destination address does not match the table entry in the routing table is forwarded according to the default route. A detailed route refers to a general route with specific forwarding information.

In fig. 1, it is assumed that the uplink main path is VM-SERVER- > LSW-1- > CORE-ROUTE, and the downlink main path is CORE-ROUTE- > LSW-1- > VM-SERVER. When the link between the CORE-ROUTE and the LSW-1 is interrupted, both the uplink and downlink main paths are interrupted, and at this time, the default ROUTE needs to be cancelled, so as to prevent some messages from being sent to the uplink and downlink main paths according to the default ROUTE. However, there may be hundreds or even thousands of detailed routes on LSW-1, so it is uncertain when the default route can be processed, and in the worst case the default route is processed last, and the VM-SERVER on LSW-1 hangs up and down continues to send packets up through LSW-1 before the default route is processed, which packets cannot reach the destination due to link down-link failure. Therefore, when there are a large number of detailed routes on LSW-1, the default route withdrawal message is sent late, which may result in an excessively long service packet loss time, i.e., an excessively long service interruption time.

Disclosure of Invention

In order to at least partially solve the above problems, the present invention provides a default route withdrawal method and apparatus.

The invention provides a method for canceling default route, which is applied to equipment operating a Border Gateway Protocol (BGP), and comprises the following steps:

when determining that the equipment has default route revocation information to be sent, carrying the default route revocation information in a first BGP message sent to a target BGP neighbor; the target BGP neighbor is an IBGP neighbor or an EBGP neighbor;

and when determining that the default route revocation information is sent to all target BGP neighbors of the equipment, locally deleting the default route indicated by the default route revocation information.

The present invention also provides a device for revoking a default route, the device being configured in a device running a border gateway protocol BGP, the device comprising:

the device comprises a default route processing unit and a target BGP neighbor, wherein the default route processing unit is used for carrying default route revocation information in a first BGP message sent to the target BGP neighbor when determining that the device has the default route revocation information to be sent; the target BGP neighbor is an IBGP neighbor or an EBGP neighbor;

and the default route deleting unit is used for locally deleting the default route indicated by the default route revocation information when determining that the default route revocation information is sent to all target BGP neighbors of the device.

According to the technical scheme of the invention, when the default route revocation information to be transmitted on the BGP running equipment is determined, the default route revocation information is carried in the first BGP message transmitted to each target BGP neighbor of the equipment, so that the default route revocation information can quickly reach each target BGP neighbor, and the problem of overlong service interruption time caused by late transmission of the default route revocation information is avoided.

Drawings

FIG. 1 is a simplified networking schematic of a prior art data center network;

FIG. 2 is a schematic diagram of a slightly more complex networking of a data center network in an embodiment of the invention;

fig. 3 is a flowchart of a method for revoking a default route according to an embodiment of the present invention;

fig. 4 is a flowchart of a specific implementation of a default route withdrawal method in an embodiment of the present invention;

fig. 5 is a block diagram of a default route withdrawal apparatus in an embodiment of the present invention;

fig. 6 is a schematic structural diagram of an apparatus for operating BGP according to an embodiment of the present invention.

Detailed Description

In order to solve the technical problems in the background art, the inventors of the present application think that in order to ensure that the sending of the default route revocation information can be prioritized from the flow, the default routing node is suspended at the head of the chain table for prioritization, that is, the default routing node is placed at the first position of the hash table. However, this processing method can only solve the problem of late issuance of the default route revocation information in a simple scenario, but cannot solve the problem of late issuance of the default route revocation information in a complex scenario as shown in fig. 2.

Fig. 2 is a schematic diagram of a slightly complex networking of a data center network in an embodiment of the present invention. Compared with fig. 1, in the networking shown in fig. 2, a core layer device over-ROUTER connected to LSW-1 is added. When the link between the CORE-ROUTE and the LSW-1 is broken and the OTHER ROUTE is sent to the LSW-1, even if the default ROUTE node is placed at the first position of the hash table corresponding to the CORE-ROUTE, because the OTHER ROUTE node and the CORE-ROUTE are equal in rank to the LSW-1, the default ROUTE sent by the CORE-ROUTE is difficult to be guaranteed to be preferentially processed, and the problem that the service interruption time is too long due to the fact that the default ROUTE cancellation message is sent later cannot be solved.

Therefore, the application example discloses a default route withdrawal method and a device, so as to solve the problem of service interruption caused by untimely withdrawal of the default route. In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present application. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.

Fig. 3 is a flowchart of a method for revoking a default route in an embodiment of the present invention. The method is applied to equipment for operating the BGP, such as a switch, a router or a server. As shown in fig. 3, the method includes:

step S310, when determining that the equipment has default route revocation information to be sent, carrying the default route revocation information in a first BGP message sent to a target BGP neighbor; the target BGP neighbor is an IBGP neighbor or an EBGP neighbor.

For example, in the networking shown in fig. 1 or fig. 2, the CORE-ROUTER issues a default route to the LSW-1, that is, the LSW-1 has a default route configured by the CORE-ROUTER, when a link between the CORE-ROUTER and the LSW-1 is broken, the LSW-1 needs to send default route revocation information to its own target BGP neighbor, and then it is determined that the LSW-1 has the default route revocation information to send.

Here, the default route withdrawal information includes: default route to be withdrawn, and instruction information to withdraw the default route. The target BGP neighbors of LSW-1 include: all BGP neighbors except the CORE-ROUTER, i.e., broadcast the default route withdraw information. Or, in an embodiment of the present invention, a manner of accurately sending the default route withdrawal information may also be adopted, where the target BGP neighbor of the LSW-1 includes: before LSW-1 is determined to have default route withdrawal information to send, LSW-1 has sent the BGP neighbors of the default route to it.

Step S320, when determining that the default route revocation information has been sent to all target BGP neighbors of the device, locally deleting the default route indicated by the default route revocation information.

And after the default route revocation information is sent to all the target BGP neighbors, deleting the local corresponding default route of the equipment.

In the method shown in fig. 3, after determining the default route revocation information to be sent on the device, the default route revocation information is carried in the first BGP message sent to the target BGP neighbor, so that the default route revocation information quickly reaches the target BGP neighbor, and the problem of too long service interruption time caused by late sending of the default route revocation message is avoided.

It should be noted that, in fig. 1 of the background art, the technical problem to be solved is only provided by taking a data center network divided into three layers as an example, and similar problems may also exist in other networks that deploy default routes using the BGP protocol. Those skilled in the art can easily predict that the technical solution shown in fig. 3 can solve the problem of delayed sending of default routing information in the data center network using the BGP protocol shown in fig. 1, and can also solve the problem of delayed sending of default routing information in other types of networks using the BGP protocol.

In an embodiment of the present invention, the step S310 in the method shown in fig. 3 includes determining that the default route withdrawal information that the present device has to send includes the following (1) or (2), or a combination of the two:

(1) and if the communication between the local device and the BGP neighbor is interrupted and the default route configured by the BGP neighbor exists on the local device, determining default route revocation information to be sent on the local device. The communication interruption here includes the interruption of a physical link and the interruption of a logical link corresponding to a service. For example, in the networking shown in fig. 1 or fig. 2, LSW-1 has a default route configured by CORE-ROUTER, and when a physical link between CORE-ROUTER and LSW-1 is broken or a logical link between CORE-ROUTER and LSW-1 is broken by corresponding services using BGP protocol, default route revocation information to be sent on LSW-1 is determined.

In this scenario, the target BGP neighbor in the method shown in fig. 3 does not include the BGP neighbor with which communication with the local device is interrupted. I.e., corresponding to the networking shown in fig. 1 or fig. 2, LSW-1 does not need to send default route withdraw information to the CORE-ROUTER.

(2) And if the equipment receives the default route revocation information sent by the BGP neighbor, the equipment is determined to have the default route revocation information to be sent. For example, in the networking shown in fig. 2, LSW-1 receives the default route revocation information sent by the OTHER-ROUTER, and LSW-1 also needs to send the default route revocation information to its target BGP neighbor, such as CORE-ROUTER and VM-SERVER.

In this scenario, the target BGP neighbor in the method shown in fig. 3 does not include the BGP neighbor that sends the default route withdraw information to the local device. For example, in the networking shown in fig. 2, LSW-1 receives the default route revocation information sent by the OTHER-ROUTER, and LSW-1 does not need to send the default route revocation information to the OTHER-ROUTER.

In an embodiment of the present invention, when it is determined that the device has default route revocation information to be sent in step S310 in the method shown in fig. 3, the step of carrying the default route revocation information in a first BGP message sent to a target BGP neighbor includes: when determining that the equipment has default route revocation information to be sent, setting a first BGP state on the equipment as a state that BGP needs to revoke the default route; when the device has a BGP message to be sent to the target BGP neighbor, judging whether the first BGP state is a state that BGP needs to withdraw default routing; if the first BGP state is a state that 'BGP needs to cancel default route', the BGP message is a first BGP message to be transmitted to a target BGP neighbor when the first BGP message is determined to be provided with default route cancellation information to be transmitted, and whether a second BGP state corresponding to the target BGP neighbor on the equipment is in a state of 'default route cancellation information transmitted' is judged; and if the second BGP state is not the state of 'default routing revocation information sent', carrying the default routing revocation information in the first BGP message and sending the first BGP message to the target BGP neighbor, and setting the second BGP state as the state of 'default routing revocation information sent'.

The method of fig. 3 further comprises: and when determining that the default route revocation information is sent to all target BGP neighbors of the equipment, setting the first BGP state on the equipment and the second BGP state corresponding to the target BGP neighbors as initial states.

Wherein the initial state of the first BGP state is: indicating that the device has no default route revocation information to be sent;

the initial state of the second BGP state is: indicating that the device has not sent default route revocation information to the corresponding target BGP neighbor.

The determining that the default route withdraw information has been sent to all target BGP neighbors of the device in the method shown in fig. 3 includes: and if the second BGP states corresponding to all the target BGP neighbors on the equipment are the states of the sent default route revocation information, determining that the default route revocation information is sent to all the target BGP neighbors of the equipment.

Fig. 4 is a flowchart of a specific implementation of a default route withdrawal method in an embodiment of the present invention. The method is applied to a device running BGP, and as shown in fig. 4, includes:

step S410, when it is determined that the device has default route revocation information to be sent, setting the first BGP state of the device to be a state of "BGP needs to revoke the default route".

In a specific implementation process, a first BGP status bit may be set. The first BGP state bit takes a value of 0 in the initial state and takes a value of 1 in the set state. When the first BGP state needs to be set to the state "BGP needs to withdraw the default route", the first BGP state is specifically set to position 1.

Step S420, when the device is to send a BGP message to the target BGP neighbor, step S430 is executed first.

The BGP message in this step may be any type of BGP message to ensure that the default route revocation information reaches the corresponding BGP neighbor at the fastest speed. Typically a BGP message that sends a route update.

Step S430, determining whether the first BGP state is the "BGP needs to withdraw the default route" state, if so, executing step S440, otherwise, executing step S470.

Step S440, determining whether the second BGP state corresponding to the target BGP neighbor is the state of "default route revocation information sent", if so, performing step S470, otherwise, performing step S450.

In the specific implementation process, a second BGP status bit needs to be set for each target BGP neighbor of the device. The second BGP status bit of 0 indicates that "default route withdrawal information has not been sent", and the second BGP status bit of 1 indicates that "default route withdrawal information has been sent".

And step S450, carrying the default route revocation information in the BGP message and sending the default route revocation information to the target BGP neighbor.

Step S460, setting the second BGP state corresponding to the target BGP neighbor to be the state of "default route revocation information sent". Step S480 is performed.

Step S470, organizing and processing other routing information according to the existing normal flow.

Step S480, judging whether the states of all target BGP neighbors of the equipment become the state of 'default route revocation information sent'; if yes, go to step S490, otherwise return to step S420.

Step S490, delete the default route from the local routing table of the device, and set the first BGP state and the second BGP states corresponding to all target BGP neighbors to the initial state.

According to the scheme, after the scheme is applied, when the default route revocation information to be sent on the BGP equipment exists, the default route revocation information must exist in the first BGP message sent to the target BGP neighbor, so that the default route revocation information can be timely and preferentially sent in any scene, and the service packet loss time is greatly shortened.

It is again emphasized that the above described scheme may be applied in any network employing the BGP protocol and default routing. Of course, the method is applicable to a network including a core layer, an aggregation layer, and an access layer, each layer of the network being divided into one or more autonomous systems, ases, that communicate between them based on BGP, such AS the data center network shown in fig. 1. That is, the problem that in the data center network shown in fig. 1, when an uplink is disconnected, a border gateway (e.g., LSW-1) of a convergence layer cannot send default route revocation information to an access layer device in time, so that uplink service packet loss time is too long can be solved.

In addition, the solution provided in the above embodiment does not need to make a large change to the existing BGP protocol, and only needs to add default route revocation information in the packet process of the BGP packet, thereby reducing the complexity of implementation and being applicable to complex networking scenarios.

The apparatus for sending default route withdrawal information in the present invention is provided based on the above-described embodiments.

Fig. 5 is a block diagram of a default route withdrawal apparatus in an embodiment of the present invention. The apparatus is configured in a device running a border gateway protocol BGP, and as shown in fig. 5, the apparatus 500 includes:

a default route processing unit 510, configured to, when determining that the device has default route revocation information to be sent, carry the default route revocation information in a first BGP message sent to a target BGP neighbor; the target BGP neighbor is an IBGP neighbor or an EBGP neighbor;

a default route deleting unit 520, configured to locally delete the default route indicated by the default route revocation information when determining that the default route revocation information has been sent to all target BGP neighbors of the device.

Wherein the default route withdrawal information includes: default route to be withdrawn, and instruction information to withdraw the default route.

In the apparatus shown in fig. 5, after determining that the default route revocation information to be sent on the device is to be sent, the default route revocation information is carried in the first BGP message sent to the target BGP neighbor, so that the default route revocation information quickly reaches the target BGP neighbor, and the problem of too long service interruption time caused by late sending of the default route revocation message is avoided.

In an embodiment of the present invention, the default route processing unit 510 is configured to determine a default route withdraw message to be sent on the local device when communication between the local device and the BGP neighbor is interrupted and a default route configured by the BGP neighbor exists on the local device; the default route configured by the BGP neighbor is the default route to be withdrawn; the target BGP neighbor does not contain the BGP neighbor with which the communication with the device is interrupted.

In an embodiment of the present invention, the default route processing unit 510 is configured to determine that the device has default route revocation information to be sent when the device receives the default route revocation information sent by a BGP neighbor; the target BGP neighbor does not contain the BGP neighbor which sends the default route revocation information to the device.

In an embodiment of the present invention, the default route processing unit 510 is configured to, when it is determined that the device has default route revocation information to be sent, set a first BGP state on the device to be a "BGP needs to revoke the default route" state; when the device has a BGP message to be sent to the target BGP neighbor, judging whether the first BGP state is a state that BGP needs to withdraw default routing; if the first BGP state is a state that 'BGP needs to cancel default route', the BGP message is a first BGP message to be transmitted to a target BGP neighbor when the first BGP message is determined to have default route cancellation information to be transmitted, and whether a second BGP state corresponding to the target BGP neighbor on the equipment is in a state of 'default route cancellation information transmitted' is judged; and if the second BGP state is not the state of 'default routing revocation information sent', carrying the default routing revocation information in the first BGP message and sending the first BGP message to the target BGP neighbor, and setting the second BGP state as the state of 'default routing revocation information sent'.

In an embodiment of the present invention, the default route deleting unit 520 is further configured to set, when it is determined that the default route revocation information has been sent to all target BGP neighbors of the local device, both a first BGP state on the local device and second BGP states corresponding to all the target BGP neighbors to initial states.

Wherein the initial state of the first BGP state is: indicating that the device has no default route revocation information to be sent; the initial state of the second BGP state is: indicating that the device has not sent default route revocation information to the corresponding target BGP neighbor.

In an embodiment of the present invention, the default route processing unit 510 is configured to determine that the default route revocation information has been sent to all target BGP neighbors of the device when the second BGP states corresponding to all target BGP neighbors on the device are the "default route revocation information sent" states.

In one embodiment of the present invention, the apparatus 500 is applied in a border gateway in a network comprising a core layer, an aggregation layer, and an access layer, each layer in the network being divided into one or more autonomous systems, ases, that communicate between them based on BGP. It should be noted that the apparatus 500 is not limited to such a network. Those skilled in the art will appreciate that the apparatus 500 may be adapted for use in any network that employs the BGP protocol and default routing.

For the device embodiment, since it basically corresponds to the method embodiment, the relevant points may be referred to the partial description of the method embodiment, and will not be repeated here. The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Fig. 6 is a schematic structural diagram of an apparatus for operating BGP according to an embodiment of the present invention. As shown in fig. 6, the apparatus 600 for operating BGP includes:

the memory 620: for storing instruction code. In one embodiment of the invention, memory 620 stores default route withdraw instructions.

The processor 610: the instruction codes stored in the memory are used for communicating with the memory, reading and executing the instruction codes, and the default route withdrawal operation disclosed by the above example of the application is realized.

Here, the memory 620 may be any electronic, magnetic, optical, or other physical storage device that can contain or store information such as executable instructions, data, and the like. For example, the machine-readable storage medium may be: RAM (random access memory), volatile memory, non-volatile memory, flash memory, a storage drive (e.g., a hard drive), a solid state drive, any type of storage disk (e.g., an optical disk, dvd, etc.), or similar storage medium, or a combination thereof.

In summary, in the technical solution of the present invention, when determining that the default route revocation information to be sent on the device is to be sent, the default route revocation information is carried in the first BGP message sent to the target BGP neighbor, so that the default route revocation information quickly reaches the target BGP neighbor, and the problem of too long service interruption time caused by late sending of the default route revocation message is avoided. In addition, the technical scheme of the invention does not need to greatly change the existing BGP protocol, and only needs to add default route revocation information in the packet packing process of the BGP message, thereby reducing the complexity of implementation and being suitable for complex networking scenes.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for withdrawing a default route, wherein the method is applied to a device running a border gateway protocol BGP, and the method comprises:

when determining that the default route revocation information is sent to all target BGP neighbors of the device, deleting the default route indicated by the default route revocation information locally;

the default route withdrawal information includes: default route to be withdrawn, and instruction information to withdraw the default route.

2. The method of claim 1, wherein the determining that the present device has default route withdraw information to send comprises:

if the communication between the local device and the BGP neighbor is interrupted and the default route configured by the BGP neighbor exists on the local device, determining a default route cancellation message to be sent on the local device; the default route configured by the BGP neighbor is the default route to be withdrawn;

the target BGP neighbor does not contain the BGP neighbor with which the communication with the device is interrupted.

3. The method of claim 1, wherein the determining that the present device has default route withdraw information to send comprises:

the equipment receives the default route revocation information sent by the BGP neighbor, and then the equipment is determined to have the default route revocation information to be sent;

the target BGP neighbor does not include the BGP neighbor that sent the default route withdraw information to the device.

4. The method according to any one of claims 1 to 3, wherein when determining that the device has default route cancellation information to be sent, carrying the default route cancellation information in a first BGP message sent to a target BGP neighbor, includes:

when determining that the equipment has default route revocation information to be sent, setting a first BGP state on the equipment as a state that BGP needs to revoke the default route;

when the device has a BGP message to be sent to the target BGP neighbor, judging whether the first BGP state is a state that BGP needs to withdraw default routing;

if the first BGP state is a state that 'BGP needs to cancel default route', the BGP message is a first BGP message to be transmitted to a target BGP neighbor when the first BGP message is determined to have default route cancellation information to be transmitted, and whether a second BGP state corresponding to the target BGP neighbor on the equipment is in a state of 'default route cancellation information transmitted' is judged;

and if the second BGP state is not the state of 'default routing revocation information sent', carrying the default routing revocation information in the first BGP message and sending the first BGP message to the target BGP neighbor, and setting the second BGP state as the state of 'default routing revocation information sent'.

5. The method of claim 4, wherein the determining that the default route withdrawal information has been sent to all target BGP neighbors of the device comprises:

and if the second BGP states corresponding to all the target BGP neighbors on the equipment are the states of the sent default route revocation information, determining that the default route revocation information is sent to all the target BGP neighbors of the equipment.

6. An apparatus for withdrawing a default route, the apparatus being configured in a device running a Border Gateway Protocol (BGP), the apparatus comprising:

a default route deleting unit, configured to delete a default route indicated by the default route revocation information locally when it is determined that the default route revocation information has been sent to all target BGP neighbors of the device;

7. The apparatus of claim 6,

the default route processing unit is configured to determine a default route revocation message to be sent on the device when communication between the device and the BGP neighbor is interrupted and a default route configured by the BGP neighbor exists on the device; the default route configured by the BGP neighbor is the default route to be withdrawn;

8. The apparatus of claim 6,

the device comprises a BGP neighbor, a default route processing unit and a route cancellation unit, wherein the BGP neighbor is used for receiving the default route cancellation information sent by the BGP neighbor and determining that the device has the default route cancellation information to be sent;

the target BGP neighbor does not contain the BGP neighbor which sends the default route revocation information to the device.

9. The apparatus according to any one of claims 6-8,

the default route processing unit is configured to set a first BGP state on the device to be a "BGP needs to withdraw the default route" state when it is determined that the device has default route withdrawal information to be sent; when the device has a BGP message to be sent to the target BGP neighbor, judging whether the first BGP state is a state that BGP needs to withdraw default routing; if the first BGP state is a state that 'BGP needs to cancel default route', the BGP message is a first BGP message to be transmitted to a target BGP neighbor when the first BGP message is determined to have default route cancellation information to be transmitted, and whether a second BGP state corresponding to the target BGP neighbor on the equipment is in a state of 'default route cancellation information transmitted' is judged; and if the second BGP state is not the state of 'default routing revocation information sent', carrying the default routing revocation information in the first BGP message and sending the first BGP message to the target BGP neighbor, and setting the second BGP state as the state of 'default routing revocation information sent'.

10. The apparatus of claim 9,

and the default route processing unit is configured to determine that the default route revocation information has been sent to all target BGP neighbors of the device when the second BGP states corresponding to all target BGP neighbors on the device are the states of the "default route revocation information sent".