CN115086228A

CN115086228A - Method and device for realizing route advertisement

Info

Publication number: CN115086228A
Application number: CN202210506616.0A
Authority: CN
Inventors: 叶金荣
Original assignee: New H3C Technologies Co Ltd
Current assignee: New H3C Technologies Co Ltd
Priority date: 2022-05-11
Filing date: 2022-05-11
Publication date: 2022-09-20

Abstract

The application provides a method and a device for realizing route announcement, wherein the method comprises the following steps: receiving a first route notification message sent by at least one second ASBR in different ASs, wherein the first route notification message comprises a first route prefix and a first BFR-ID set; according to the first routing prefix, locally searching a first BFR agent table item matched with the first routing prefix, wherein the first BFR agent table item comprises the first BFR agent prefix; and sending a second route notification message to the first network equipment, wherein the second route notification message comprises a first BFR agent prefix, a first BFR-ID set and a BFR agent mark, so that the first network equipment determines a BIER route reaching each BFER based on the first BFR agent prefix according to the BFR agent mark.

Description

Method and device for realizing route advertisement

Technical Field

The present application relates to the field of communications technologies, and in particular, to a method and an apparatus for implementing a route advertisement.

Background

Bit index based Explicit Replication (BIER for short) is a new multicast technology. In the BIER domain, Bit-Forwarding Egress Routers (in english: Bit-Forwarding Egress Routers, abbreviated as BFERs) of each BIER sub-domain are required to be configured with a BFR-ID (Bit-Forwarding router identifier) value, and the value is unique in the BIER sub-domain.

Taking 256 BFERs in the networking as an example, each BFER needs to be configured with a unique identifier BFR-ID within 1-256, a BFER set (also called a destination node set) is represented by a Bit String (Bit String) of 256 bits, and the position or index of each Bit in the Bit String represents one BFER.

The BFR-ID information in the BIER sub-domain, AS well AS other information (e.g., the IP address of the BFR), may be flooded within the Autonomous System (AS) via an Interior Gateway Protocol (IGP), e.g., IS-IS Protocol. Each BFR in the area establishes a BIER Forwarding Table, namely a Bit Index Forwarding Table (English: Bit Index Forwarding Table, abbreviated as BIFT), which guides the BFR to forward the BIER message.

Currently, an Autonomous System Border Router (ASBR) at the edge of an AS supports cross-domain publication of BIER information, and the ASBR collects all BFR-IDs received from an external AS. The ASBR announces the collected BFR id set to other routers in the AS through an Internal Border Gateway Protocol (IBGP); or advertised to other routers within the AS by IGP.

As shown in fig. 1, fig. 1 is a schematic diagram of a conventional networking system for implementing cross-domain distribution of BIER information. In fig. 1, ASBR1-1 within AS100 performs BFR ID aggregation of BFR-IDs received from AS200 of 1-64 and from AS300 of 65-128, with the aggregated BFR-IDs aggregated to 1-128. Announced to other routers within AS100 by the IBGP. The routing prefix is a BFR prefix (prefix) of the ASBR 1-1: 2001:2:2F: 1/128; or advertised to other routers within AS100 by IGP. The routing prefix is BFR prefix of ASBR 1-1: 2001:2:2F: 1/128.

However, in the conventional process of distributing BIER information across domains, the following defects also occur: 1) BFR-IDs issued between ASBR1-1 and ASBR1-2 for the same external AS will form a loop. That is, the ASBR1-1 and the ASBR1-2 cannot advertise the BFR-ID issued by the external AS to each other through IBGP.

2) The process of implementing horizontal segmentation on an ASBR is complex. For example, when ASBR1-1 of AS100 advertises BIER information of AS100 to ASBR2-1 of AS200, the received BFR-ID: 1-128 are carried within the BIER message. Thus, after receiving the BIER information, ASBR2-1 acquires the BFR-ID reported by itself to ASBR1-1 again: 1-64. At this time, ASBR2-1 is needed to implement loop filtering. If ASBR1-1 is advertising BIER information, excluding BFR-ID from ASBR2-1 report: 1-64, then, the processing on ASBR1-1 is complex.

Disclosure of Invention

In view of this, the present application provides a method and an apparatus for implementing a route advertisement, so AS to solve the problems that, in the existing process of issuing BIER information across domains, BFR-IDs issued by external ASs cannot be mutually advertised by IBGP among ASBRs, and the process of implementing horizontal segmentation on the ASBRs is complex.

In a first aspect, the present application provides a method for implementing route advertisement, where the method is applied to a first ASBR, where the first ASBR is located in a first AS, and the first AS further includes a first network device, where the method includes:

receiving a first route advertisement message sent by at least one second ASBR in different ASSs, wherein the first route advertisement message comprises a first route prefix and a first BFR-ID set, the first route prefix is the BFR prefix of the second ASBR, the first BFR-ID set comprises at least one BFR-ID, each BFR-ID represents one BFER, and the BFER and the second ASBR are in the same AS;

according to the first routing prefix, locally searching a first BFR proxy table item matched with the first routing prefix, wherein the first BFR proxy table item comprises a first BFR proxy prefix;

and sending a second route notification message to the first network equipment, wherein the second route notification message comprises the first BFR agent prefix, the first BFR-ID set and a BFR agent mark, so that the first network equipment determines a BIER route reaching each BFER based on the first BFR agent prefix according to the BFR agent mark.

In a second aspect, the present application provides an apparatus for implementing a route advertisement, where the apparatus is applied to a first ASBR, and the first ASBR is located in a first AS, and further includes a first network device in the first AS, and the apparatus includes:

a receiving unit, configured to receive a first route advertisement packet sent by at least one second ASBR located in different ASs, where the first route advertisement packet includes a first route prefix and a first BFR-ID set, the first route prefix is a BFR prefix of the second ASBR, the first BFR-ID set includes at least one BFR-ID, each BFR-ID represents a BFER, and the BFER and the second ASBR are located in the same AS each other;

a searching unit, configured to locally search, according to the first routing prefix, a first BFR proxy table entry that matches the first routing prefix, where the first BFR proxy table entry includes a first BFR proxy prefix;

a sending unit, configured to send a second route advertisement packet to the first network device, where the second route advertisement packet includes the first BFR agent prefix, the first BFR-ID set, and a BFR agent label, so that the first network device determines, according to the BFR agent label, a BIER route that reaches each BFER based on the first BFR agent prefix.

In a third aspect, the present application provides a network device comprising a processor and a machine-readable storage medium storing machine-executable instructions executable by the processor, the processor being caused by the machine-executable instructions to perform the method provided by the first aspect of the present application.

Therefore, by applying the method and apparatus for implementing the route advertisement provided by the present application, a first ASBR receives a first route advertisement packet sent by at least one second ASBR located in different ASs, where the first route advertisement packet includes a first route prefix and a first BFR-ID set, the first route prefix is a BFR prefix of the second ASBR, the first BFR-ID set includes at least one BFR-ID, each BFR-ID represents one BFER, and the BFER and the second ASBR are located in the same AS each other; according to the first routing prefix, the first ASBR locally searches a first BFR proxy table item matched with the first routing prefix, wherein the first BFR proxy table item comprises the first BFR proxy prefix; and the first ASBR sends a second route notification message to the first network equipment, wherein the second route notification message comprises a first BFR proxy prefix, a first BFR-ID set and a BFR proxy mark, so that the first network equipment determines a BIER route reaching each BFER based on the first BFR proxy prefix.

In this way, when the first ASBR distributes BIER information belonging to the same peer AS in the first AS, using the BFR proxy prefixes of the BFR proxies configured for different peer ASs, the first ASBR distributes BIER information using the BFR proxy prefix configured for the peer, so that each network device in the first AS calculates a BIER route to each BFER in the peer AS based on the BFR proxy prefix. The problem that in the existing process of issuing BIER information across domains, BFR-ID issued by external AS cannot be mutually notified by IBGP between ASBRs and the process of realizing horizontal segmentation on the ASBRs is complex is solved.

Drawings

Fig. 1 is a schematic diagram of a conventional networking system for realizing cross-domain publication of BIER information;

fig. 2 is a flowchart of a method for implementing a route advertisement according to an embodiment of the present application;

fig. 3 is a schematic diagram of a Sub TLV structure provided in an embodiment of the present application;

FIG. 4 is a schematic diagram of Sub-TLVs provided in the embodiment of the present application;

FIG. 5 is a diagram illustrating another Sub-TLVs field provided by an embodiment of the present application;

FIG. 6 is a schematic diagram illustrating Sub-TLVs provided in an embodiment of the present application;

FIG. 7 is a diagram illustrating Sub-TLVs according to an embodiment of the present application;

fig. 8 is a schematic diagram of a networking for realizing cross-domain BIER information distribution according to the embodiment of the present application;

fig. 9 is a structural diagram of an apparatus for implementing a route advertisement according to an embodiment of the present application;

fig. 10 is a hardware structure of a network device according to an embodiment of the present application.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings in which the same 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 corresponding 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.

The following describes in detail a method for implementing a route advertisement provided in an embodiment of the present application. Referring to fig. 2, fig. 2 is a flowchart of a method for implementing a route advertisement according to an embodiment of the present application. The method is applied to a first ASBR. The method for implementing the route advertisement provided by the embodiment of the application may include the following steps.

Step 210, receiving a first route advertisement packet sent by at least one second ASBR located in different ASs, where the first route advertisement packet includes a first route prefix and a first BFR-ID set, the first route prefix is a BFR prefix of the second ASBR, the first BFR-ID set includes at least one BFR-ID, each BFR-ID represents a BFER, and the BFER and the second ASBR are located in the same AS each other.

Specifically, the first AS includes a plurality of Bit Forwarding Routers (BFRs), and the plurality of BFRs are divided into BFRs AS ASBRs and BFRs AS non-ASBRs according to positions of the BFRs. Wherein the first AS includes a first BFR, a second BFR, a third BFR, and so on. The first and second BFRs may be ASBRs, e.g., the first and third ASBRs, and the third BFR may be a non-ASBR.

The embodiment of the present application takes a first ASBR as an example for description. The third ASBR and non-ASBR BFRs are collectively referred to as a first network device.

Similarly, the second AS includes a plurality of BFRs, which are divided into BFRs AS ASBRs and BFRs AS non-ASBRs according to positions of the BFRs. Wherein a fourth BFR, a fifth BFR, and so on are included within the second AS. The fourth BFR may be an ASBR, e.g., the second ASBR and the fifth BFR may be a non-ASBR.

In the embodiment of the present application, a second ASBR in a second AS is taken AS an example for description. The second ASBR has established an External Border Gateway Protocol (EBGP) neighbor with the first ASBR. The second ASBR collects the BFR-ID of each BFER within the second AS and advertises to the first ASBR via EBGP.

And the second ASBR generates a first route notification message, wherein the first route notification message comprises a first route prefix and a first BFR-ID set.

The first routing prefix is a BFR prefix of the second ASBR, at least one BFR-ID is included in the first BFR-ID set, each BFR-ID represents one BFER, and the BFER and the second ASBR are in the same AS.

And the second ASBR sends the first route notification message to the first ASBR. And after receiving the first route notification message, the first ASBR acquires a first route prefix and a first BFR-ID set from the first route notification message.

It should be noted that the network is divided into multiple ASs, for example, a third AS, a fourth AS, and so on, and after an EBGP neighborhood is established between an ASBR in each AS and a first ASBR, a route advertisement message is sent to the first ASBR. The first ASBR receives a first route notification message sent by at least one second ASBR in different ASs.

If there are multiple ASBRs in each AS, each ASBR also sends a route advertisement message to the first ASBR after establishing an EBGP neighborhood with the first ASBR.

The second AS, the third AS, and the fourth AS may all be collectively referred to AS different second AS.

Step 220, according to the first routing prefix, locally searching a first BFR proxy table entry matched with the first routing prefix, where the first BFR proxy table entry includes the first BFR proxy prefix.

Specifically, according to the description in step 210, after the first ASBR acquires the first routing prefix and the first BFR-ID set, the first ASBR locally searches for the first BFR proxy table entry matching the first routing prefix according to the first routing prefix. The first BFR proxy table entry includes a first BFR proxy prefix.

Optionally, before the first ASBR receives the first route advertisement packet sent by the second ASBR, the first ASBR locally configures a BFR proxy and creates a BFR proxy entry.

In one scenario, a first ASBR establishes an EBGP connection with at least one second ASBR within different second ASs, respectively. For example, a first ASBR establishes an EBGP connection with a second ASBR within a second AS; the first ASBR establishes an EBGP connection with a third ASBR within a third AS.

The first ASBR determines ASBRs, e.g., second ASBRs, third ASBRs, that establish EBGP neighbors with itself and that are within different AS than the first ASBR.

And the first ASBR respectively configures a corresponding BFR proxy for the AS where each ASBR is located, and configures a BFR proxy prefix for each BFR proxy. Wherein the format of the BFR proxy prefix is a host address format, which is used for announcing BIER information received from different ASBRs of the same opposite AS in the first AS.

For example, a first ASBR configures a first BFR proxy for a second AS, a second BFR proxy for a third AS, and a BFR proxy prefix for each BFR proxy.

In another scenario, the first ASBR establishes an EBGP connection with at least one second ASBR within one second AS, respectively. For example, a first ASBR establishes an EBGP connection with a second ASBR within a second AS; the first ASBR establishes an EBGP connection with a third ASBR within the second AS.

For example, the first ASBR configures a first BFR proxy for the second AS and a BFR proxy prefix for the first BFR proxy.

And the first ASBR creates a BFR proxy table entry and generates a BFR proxy table entry corresponding to each AS. The BFR proxy entry includes a BFR proxy prefix field, an AS identification field, a BFR prefix field of the second ASBR, and a BFR-ID set field.

In summary, when a plurality of ASBRs in the first AS are connected to ASBRs of the same peer AS, the same BFR proxy is configured in each ASBR of the first AS, respectively, for the peer ASBRs.

When one ASBR in the first AS is connected with a plurality of ASBRs of the same opposite terminal AS, the same BFR proxy is configured in the ASBR in the first AS according to the opposite terminal ASBR.

Optionally, after the first ASBR locally searches for the first BFR proxy entry matching the first routing prefix, the first ASBR stores the first routing prefix and the first BFR-ID set to a field corresponding to the first BFR proxy entry.

It is understood that, when the BFR proxy table entry is generated, the BFR proxy prefix field and the AS identification field fill in the corresponding BFR proxy prefix and AS identification.

Step 230, sending a second route advertisement packet to the first network device, where the second route advertisement packet includes the first BFR agent prefix, the first BFR-ID set, and a BFR agent label, so that the first network device determines, according to the BFR agent label, a BIER route to reach each BFER based on the first BFR agent prefix.

Specifically, according to the description in step 220, after the first ASBR locally finds the first BFR proxy entry matching the first routing prefix, the first ASBR obtains the first BFR proxy prefix from the first BFR proxy entry.

And the first ASBR generates a second route notification message, wherein the second route notification message comprises a first BFR agent prefix, a first BFR-ID set and a BFR agent mark.

In the first AS, the first ASBR sends a second route announcement message to the first network equipment. And the first network equipment receives the second route notification message and acquires a first BFR agent prefix and a first BFR-ID set from the second route notification message. If the first network device further obtains the BFR proxy label from the second route advertisement message, the first network device determines that route calculation can be performed according to the existing algorithm based on the first BFR proxy prefix when calculating the BIER route to each BFER.

When the first network device receives the unicast route reachability information with BIER information from the plurality of BFRs, because the proxy prefixes in the unicast route reachability information are the same, one of the routes may be selected as the optimal route according to the existing route optimization method. And the first network equipment adds the BIER route in the BIRT by using the BIER information corresponding to the optimal route, and further generates the forwarding information in the corresponding BIFT.

Optionally, the second route advertisement message may specifically be an IBGP update message or an IGP LSP message.

The sending, by the first ASBR, the second route advertisement packet to the first network device specifically includes: the first ASBR sends an IBGP update message or an IGP Link State Protocol (LSP) message to the third ASBR;

or;

and the first ASBR sends an IBGP update message or an IGP LSP message to the BFR of the non-ASBR.

Optionally, the IBGP update message includes an NLRI and a path attribute, and the path attribute is not limited to the following attributes: BIER Path Attribute (BIER Path Attribute). The NLRI carries BFR proxy prefix, BIER path attribute is TLV coding: a Type (Type) field, a Type Code (Type Code) field, and a value (value) field.

Wherein, the value of the Type field is Optional & Transtive; the value of the Type Code field is assigned by IANA and is currently configured as a decimal number of 70. The value field includes a Sub TLV structure. As shown in fig. 3, fig. 3 is a schematic structural diagram of a Sub TLV provided in an embodiment of the present application. In fig. 3, the Sub TLV structure includes a Type (Type) field, a Length (Length) field, a Sub domain ID field (SD), a BFR-ID field, a Reserved (Reserved) field, and a Sub TLV (Sub-TLVs) field, and the Sub-TLVs field may be plural.

A bit (marked as P) is occupied in the Reserved field to carry a BFR agent mark, the value of the bit is set to be 1, which indicates that the BFR agent mark is carried, namely, NLRI carries a prefix corresponding to the BFR agent; the Sub-TLVs field includes a first Sub-TLVs field that carries a set of BFR-IDs. As shown in fig. 4, fig. 4 is a schematic diagram of Sub-TLVs fields provided in the embodiment of the present application. In FIG. 4, the first Sub-TLVs field includes a Type (Type) field, a Length (Length) field, a BFR-ID field, and a BFR-ID range (BFR-ID range) field. The BFR-ID field bears the initial value of the BFR-ID, the BFR-ID range field bears the number of the BFR-ID, and the two fields represent the continuous value-taking section of the BFR-ID in the first AS. The first Sub-TLVs field may include at least one value field depending on a BFR-ID configuration of respective BFRs within the first AS.

In the embodiment of the application, a second Sub-TLVs field is further included in the Sub-TLVs field, and the second Sub-TLVs field carries a BIER encapsulation type and information for generating a bit. As shown in fig. 5, fig. 5 is a schematic diagram of another Sub-TLVs field provided in the embodiment of the present application. In FIG. 5, the second Sub-TLVs field includes a Type (Type) field, a Length (Length) field, a BSL field, a Max-SI field, and a BIFT ID field. Different values of the Type field identify different BIER encapsulation types (such AS MPLS encapsulation types, IPv6 BIER encapsulation types and the like), the BSL field is BSL supported under Sub-domain, and occupies 4 bits, the Max-SI field is SI corresponding to the maximum BFR-ID in the first AS, and occupies 8 bits, and the BIFT ID field is the minimum value of the ID section of the BIFT forwarding table, and occupies 20 bits.

Optionally, the IGP LSP packet includes prefix reachability information. For example, the IS-IS accessibility Prefix TLV includes information not limited to: prefix, BIER information Sub TLV (BIER Info Sub-TLV) structure. Wherein the prefix carries a BFR proxy prefix. The BIER Info Sub-TLV structure includes a Sub-TLVs field.

The Sub TLV structure includes a first Sub-TLVs field and a second Sub-TLVs field.

As shown in fig. 6, fig. 6 is a schematic diagram of Sub-TLVs fields according to an embodiment of the present application. In fig. 6, the first Sub-TLVs field includes a Type field, a Length field, and a Reserved field. A bit (marked as P) occupied in the Reserved field carries a BFR agent flag, and the value of the P field is set to 1, which indicates that the BFR agent flag is carried, that is, the prefix attribute carries the prefix corresponding to the BFR agent.

As shown in fig. 7, fig. 7 is a schematic diagram of Sub-TLVs fields according to an embodiment of the present application. In FIG. 7, the second Sub-TLVs field includes a Type field, a Length field, a BFR-ID range field. The BFR-ID field bears the initial value of the BFR-ID, the BFR-ID range field bears the number of the BFR-ID, and the two fields represent the continuous value-taking section of the BFR-ID in the first AS. The first Sub-TLVs field may include at least one value segment depending on a BFR-ID configuration of respective BFRs within the first AS.

The following describes in detail a method for implementing a route advertisement provided in an embodiment of the present application. Referring to fig. 8, fig. 8 is a schematic diagram of a networking for implementing cross-domain BIER information distribution provided in the embodiment of the present application.

The group network includes three ASs, AS100, AS200, and AS 300. The AS100 comprises ASBR1-1, ASBR1-2, R1-1 and R1-2. The AS200 comprises ASBR2-1, ASBR2-2, R2-1 and R2-2. The AS300 comprises ASBR3-1, ASBR3-2, R3-1 and R3-2.

ASBR1-1 establishes EBGP connection with ASBR2-1 and ASBR3-1 respectively; ASBR1-2 establishes EBGP connections with ASBR2-2 and ASBR3-2 respectively.

BFR agents are arranged in each ASBR, and ASBR1-1 and ASBR1-2 are taken as examples for explanation.

In ASBR1-1, the BFR agent is configured according to the opposite terminal ASBR:

configuring a BFR proxy 1 for ASBR2-1 in AS200, BFR proxy 1 prefix: 2001:2:2F: 20, representing AS 200; configuring a BFR proxy 2 for ASBR3-1 in AS300, wherein the prefix of BFR proxy 2 is AS follows: 2001:2:2F: 30, representing AS 300.

Similarly, in ASBR1-2, the BFR agent is configured according to the opposite-end ASBR:

configuring a BFR proxy 1 for ASBR2-2 in AS200, BFR proxy 1 prefix: 2001:2:2F: 20, representing AS 200; configuring a BFR proxy 2 for ASBR3-2 in AS300, wherein the BFR proxy 2 prefix: 2001:2:2F: 30, representing AS 300;

configuring the BFR agent as described above may simplify the configuration:

in ASBR1-1, configuring BFR proxy according to opposite terminal AS:

configuring BFR agent 1 for AS200, BFR agent 1 prefix: 2001:2:2F: 20, representing AS 200; BFR agent 2 is configured for AS300, BFR agent 2 prefix: 2001:2:2F: 30, representing AS 300.

In ASBR1-2, configuring BFR proxy according to opposite terminal AS:

configuring BFR agent 1 for AS200, BFR agent 1 prefix: 2001:2:2F: 20, representing AS 200; configuring BFR proxy 2 for AS300, BFR proxy 2 prefix: 2001:2:2F: 30, representing AS 300.

After the BFR agent 1 and the BFR agent 2 are configured in the ASBR1-1, a BFR agent table is generated. In the embodiment of the present application, the BFR proxy table includes two entries, which are a BFR proxy table entry 1 and a BFR proxy table entry 2. The BFR proxy table entry comprises a BFR proxy prefix field, an AS identification field, a BFR prefix field of an ASBR and a BFR-ID set field.

Table 1BFR proxy table

BFR proxy prefix field	AS identification field	BFR prefix field of ASBR	BFR-ID set field
				2001:2:2F::20	AS 200
2001:2:2F::30	AS 300

As shown in table 1, ASBR1-1 has not received the EBGP update message sent by ASBR2-1 and ASBR3-1, and therefore, the BFR prefix field and the BFR-ID set field of the ASBR are both empty.

Similarly, the BFR proxy table is also configured in ASBR1-2 and will not be repeated here.

The ASBR interaction route advertisement of the established EBGP is described by taking AS an example that ASBR2-1 and ASBR3-1 send an EBGP update message to ASBR1-1, and ASBR1-1 sends an IBGP update message or an IGP LSP message in AS 100.

ASBR2-1 generates EBGP update message, which includes BIER path attributre and NLRI. Wherein, the BIER path attribute comprises a BFR-ID set, specifically 1-64; the NLRI includes BFR prefix of ASBR2-1, specifically: 2002:2:2F: 1/128.

Similarly, ASBR3-1 generates an EBGP update message, where the EBGP update message includes BIER path attribute and NLRI. Wherein, the BIER path attribute comprises a BFR-ID set, specifically 65-128; the NLRI includes BFR prefix of ASBR3-1, which is specifically: 2003:2:2F: 1/128.

After receiving the EBGP update message sent by ASBR2-1, ASBR1-1 acquires the BFR prefix and BFR-ID set of ASBR 2-1. After receiving the EBGP update message sent by ASBR3-1, ASBR1-1 acquires the BFR prefix and BFR-ID set of ASBR 3-1.

The ASBR1-1 stores the acquired BFR prefix of ASBR2-1, the acquired BFR prefix of ASBR3-1 and two BFR-ID sets in the above table 1.

Table 1BFR proxy table

BFR proxy prefix field	AS identification field	BFR prefix field of ASBR	BFR-ID set field
				2001:2:2F::20	AS 200	2002:2:2F::1/128	1-64
2001:2:2F::30	AS 300	2003:2:2F::1/128	65-128

ASBR1-1 advertises within AS100 information of BFRs within AS200, 300. ASBR1-1 generates a first route advertisement message and sends the first route advertisement message at all network devices within AS 100.

In the embodiment of the application, if an IBGP neighbor is established between ASBR1-1 and ASBR1-2, R1-1, and R1-2, the first route advertisement message is specifically an IBGP update message; if the ASBR1-1 establishes an IGP neighbor with the ASBR1-2, R1-1, or R1-2, the first route advertisement packet IS specifically an IGP LSP packet (which may also be referred to as a flooding packet), for example, an LSP packet in IS-IS.

AS shown below, ASBR1-1 sends an IBGP update message to all network devices in AS 100:

it can be understood that the ASBR1-1 may carry information of BFRs in different ASs in one IBGP update message, or may carry information in multiple IBGP update messages, and the embodiment of the present application does not limit the sending process. ASBR1-1 sends IGP messages to all network devices within AS 100:

it can be understood that the ASBR1-1 may carry information of BFRs in different ASs in one IGP message, or may carry information in multiple IGP messages, and the sending process is not limited in this embodiment of the present application.

In the embodiment of the present application, ASBR2-2 and ASBR3-2 also send EBGP update messages to ASBR1-2, and ASBR1-2 sends IBGP update messages or IGP LSP messages in AS100, which is not described again here.

After receiving the first routing packet, the network device in the AS100 performs routing calculation, and generates a BIER route and BIER forwarding information. The following description will be made by taking R1-1 as an example.

After receiving the IBGP update message sent by the ASBR1-1 and the IBGP update message sent by the ASBR1-2, the R1-1 obtains prefixes of the BFR proxy 1 from the IBGP update messages: 2001:2:2F: 20/128, BFR-ID set (1-64). If R1-1 acquires the label of BFR agent 1 from the IBGP update message, R1-1 determines that when calculating each BFER route to the AS200, it can calculate the route according to the existing algorithm based on the prefix of BFR agent 1.

When R1-1 receives unicast route reachability information with BIER information from multiple BFRs, the route received from ASBR1-1 may be selected as the optimal route according to the existing route preference method because the proxy prefixes in the unicast route reachability information are the same. And the R1-1 adds the BIER route in the BIRT by using the BIER information corresponding to the optimal route, and further generates the forwarding information in the corresponding BIFT. The BFR _ NBR field included within the BIFT stores the ASBR1-1 identification. The forwarding information in the BIFT is:

TABLE 2 BIFT

BIFT-ID(BSL/SD/SI)	F-BM	BFR_NBR
			2000(3/1/1)	0000 … 000011 … 11(192 pieces 0, 64 pieces 1)	ASBR1-1

Through the processing of the BFR agent 1, all network devices in the AS100 can perform route calculation and optimization in a unicast route prefix manner when performing route calculation on BFERs arriving in other ASs.

Based on the same inventive concept, the embodiment of the application also provides a device for realizing the route advertisement corresponding to the method for realizing the route advertisement. Referring to fig. 9, fig. 9 is a device for implementing a route advertisement provided in an embodiment of the present application, where the device is applied to a first ASBR, where the first ASBR is located in a first AS, and the first AS further includes a first network device, and the device includes:

a receiving unit 910, configured to receive a first route advertisement packet sent by at least one second ASBR located in different ASs, where the first route advertisement packet includes a first route prefix and a first BFR-ID set, the first route prefix is a BFR prefix of the second ASBR, the first BFR-ID set includes at least one BFR-ID, each BFR-ID represents a BFER, and the BFER and the second ASBR are located in the same AS each other;

a searching unit 920, configured to locally search, according to the first routing prefix, a first BFR proxy table entry that matches the first routing prefix, where the first BFR proxy table entry includes a first BFR proxy prefix;

a sending unit 930, configured to send a second route advertisement packet to the first network device, where the second route advertisement packet includes the first BFR agent prefix, the first BFR-ID set, and a BFR agent label, so that the first network device determines, according to the BFR agent label, a BIER route that reaches each BFER based on the first BFR agent prefix.

Optionally, the apparatus further comprises: a determining unit (not shown in the figure) configured to determine at least one second ASBR establishing an EBGP neighbor with the first ASBR and being within a different AS from the first ASBR;

a configuration unit (not shown in the figure), configured to configure a corresponding BFR proxy for the AS where each second ASBR is located, and configure a BFR proxy prefix for each BFR proxy;

a generating unit (not shown in the figure) configured to generate a BFR proxy entry, which includes a BFR proxy prefix field, an AS identification field, a BFR prefix field of the second ASBR, and a BFR-ID set field.

Optionally, the configuring unit (not shown in the figure) is specifically configured to, when the first ASBR is connected to at least one second ASBR in different second ASs, configure a corresponding BFR proxy for the second AS in which each second ASBR is located;

or;

and when the first ASBR is connected with at least one second ASBR in a second AS, configuring a corresponding BFR proxy for the second AS where the at least one second ASBR is located.

Optionally, the apparatus further comprises: a storage unit (not shown in the figure), configured to store the first routing prefix and the first BFR-ID set in a field corresponding to the first BFR proxy table entry.

Optionally, the first network device comprises a third ASBR and a non-ASBR BFR;

the second route notification message comprises an IBGP update message or an IGP LSP message;

the sending unit 930 is specifically configured to send the IBGP update message or the IGP LSP message to the third ASBR;

or;

and sending the IBGP update message or the IGP LSP message to the BFR of the non-ASBR.

Optionally, the IBGP update message includes a BIER path attribute, where the BIER path attribute includes a value field, and the value field includes a Sub TLV structure;

the Sub TLV structure comprises a reserved field and a Sub-TLVs field, wherein the reserved field carries the BFR agent mark; the Sub-TLVs field comprises a first Sub-TLVs field, and the first Sub-TLVs field carries the BFR-ID set.

Optionally, the LSP packet includes a BIER information Sub TLV structure, where the Sub TLV structure includes a first Sub-TLVs field and a second Sub-TLVs field, where the first Sub-TLVs field carries the BFR proxy tag, and the second Sub-TLVs field carries the BFR-ID set.

Therefore, by applying the apparatus for implementing route advertisement provided by the present application, a first ASBR receives a first route advertisement packet sent by at least one second ASBR located in different ASs, where the first route advertisement packet includes a first route prefix and a first BFR-ID set, the first route prefix is a BFR prefix of the second ASBR, the first BFR-ID set includes at least one BFR-ID, each BFR-ID represents one BFER, and the BFER and the second ASBR are located in the same AS each other; according to the first routing prefix, the first ASBR locally searches a first BFR proxy table item matched with the first routing prefix, wherein the first BFR proxy table item comprises the first BFR proxy prefix; and the first ASBR sends a second route notification message to the first network equipment, wherein the second route notification message comprises a first BFR proxy prefix, a first BFR-ID set and a BFR proxy mark, so that the first network equipment determines a BIER route reaching each BFER based on the first BFR proxy prefix.

Based on the same inventive concept, the embodiment of the present application further provides a network device, as shown in fig. 10, including a processor 1010, a transceiver 1020, and a machine-readable storage medium 1030, where the machine-readable storage medium 1030 stores machine-executable instructions capable of being executed by the processor 1010, and the processor 1010 is caused by the machine-executable instructions to perform an implementation method of the route advertisement provided by the embodiment of the present application. The foregoing implementation apparatus of the route advertisement shown in fig. 9 can be implemented by using a hardware structure of a network device as shown in fig. 10.

The computer-readable storage medium 1030 may include a Random Access Memory (RAM) and a Non-volatile Memory (NVM), such as at least one disk Memory. Alternatively, the computer-readable storage medium 1030 may also be at least one memory device located remotely from the processor 1010.

The Processor 1010 may be a general-purpose Processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; the Integrated Circuit can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components.

In the embodiment of the present application, the processor 1010 is caused by machine executable instructions, by reading the machine executable instructions stored in the machine readable storage medium 1030, to implement the implementation method of the processor 1010 itself and the invoking transceiver 1020 to execute the route advertisement described in the embodiment of the present application.

Additionally, the present application provides a machine-readable storage medium 1030, where the machine-readable storage medium 1030 stores machine-executable instructions, and when invoked and executed by the processor 1010, the machine-executable instructions cause the processor 1010 itself and the invoking transceiver 1020 to perform the method for implementing the route advertisement described in the present application.

The implementation process of the functions and actions of each unit in the above device is specifically described in the implementation process of the corresponding step in the above method, and is not described herein again.

For the device embodiments, since they substantially correspond to the method embodiments, reference may be made to the partial description of the method embodiments for relevant points. 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 can be selected according to actual needs to achieve the purpose of the scheme of the application. One of ordinary skill in the art can understand and implement it without inventive effort.

For the embodiment of the implementation apparatus and the machine-readable storage medium of the route advertisement, since the content of the related method is substantially similar to that of the foregoing method embodiment, the description is relatively simple, and for the relevant points, reference may be made to part of the description of the method embodiment.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for implementing route advertisement, the method being applied to a first ASBR, the first ASBR being in a first AS, the first AS further including a first network device, the method comprising:

2. The method of claim 1, wherein prior to receiving the first route advertisement packet sent by at least one second ASBR located in a different AS, the method further comprises:

determining at least one second ASBR that establishes an EBGP neighbor with the first ASBR and is within a different AS than the first ASBR;

configuring corresponding BFR agents for the AS where each second ASBR is located, and configuring a BFR agent prefix for each BFR agent;

and generating a BFR proxy table item, wherein the BFR proxy table item comprises a BFR proxy prefix field, an AS identification field, a BFR prefix field of the second ASBR and a BFR-ID set field.

3. The method according to claim 2, wherein the configuring a corresponding BFR agent for the AS in which each second ASBR is located respectively comprises:

when the first ASBR is connected with at least one second ASBR in different second ASBRs, configuring a corresponding BFR proxy for the second AS where each second ASBR is located;

or;

4. The method of claim 1, wherein after locally searching for the first BFR proxy entry matching the first routing prefix, the method further comprises:

and storing the first routing prefix and the first BFR-ID set into a field corresponding to the first BFR proxy table entry.

5. The method of claim 1, wherein the first network device comprises a third ASBR and a non-ASBR BFR;

the sending the second route advertisement packet to the first network device specifically includes:

sending the IBGP update message or the IGP LSP message to the third ASBR;

or;

6. The method of claim 5, wherein the IBGP update message comprises a BIER path attribute, wherein the BIER path attribute comprises a value field, and wherein the value field comprises a Sub TLV structure;

7. The method of claim 5, wherein the IGP LSP packet includes a BIER information Sub TLV structure, wherein the Sub TLV structure includes a first Sub-TLVs field and a second Sub-TLVs field, wherein the first Sub-TLVs field carries the BFR proxy tag, and wherein the second Sub-TLVs field carries the BFR-ID set.

8. An apparatus for implementing a route advertisement, the apparatus being applied to a first ASBR, the first ASBR being located within a first AS, the first AS further including a first network device, the apparatus comprising:

9. The apparatus of claim 8, further comprising:

a determining unit, configured to determine at least one second ASBR that establishes an EBGP neighbor with the first ASBR and is within a different AS from the first ASBR;

the configuration unit is used for configuring corresponding BFR agents for the AS where each second ASBR is located and configuring a BFR agent prefix for each BFR agent;

and the generating unit is used for generating a BFR proxy table entry, wherein the BFR proxy table entry comprises a BFR proxy prefix field, an AS identification field, a BFR prefix field of the second ASBR and a BFR-ID set field.

10. The apparatus according to claim 9, wherein the configuring unit is specifically configured to, when the first ASBR is connected to at least one second ASBR in different second ASs, configure a corresponding BFR proxy for the second AS in which each second ASBR is located;

or;

and when the first ASBR is connected with at least one second ASBR of a second AS, configuring a corresponding BFR proxy for the second AS where the at least one second ASBR is located.

11. The apparatus of claim 8, further comprising:

a storage unit, configured to store the first routing prefix and the first BFR-ID set in a field corresponding to the first BFR proxy table entry.

12. The apparatus of claim 8, wherein the first network device comprises a third ASBR and a non-ASBR BFR;

the sending unit is specifically configured to send the IBGP update packet or the IGP LSP packet to the third ASBR;

or;

13. The apparatus of claim 12, wherein the IBGP update message comprises a BIER path attribute, wherein the BIER path attribute comprises a value field, and wherein the value field comprises a Sub TLV structure;

14. The apparatus of claim 12, wherein the LSP packet comprises a BIER information Sub TLV structure, wherein the Sub TLV structure comprises a first Sub-TLVs field that carries the BFR proxy tag and a second Sub-TLVs field that carries the BFR-ID set.