Routing notification method and electronic device

Abstract

The present application provides a route announcement method and an electronic device. In this embodiment, each ASBR in the first AS connected to the second AS announces the network reachability information corresponding to the same BFR group prefix to the second AS (carrying BIER Path Attribute, BIER Path Attribute at least includes the BFR ID of each BFR in the first AS), and when the ASBR in the second AS receives the network reachability information announced by the ASBR in the first AS, it will continue to announce the BIER route of the same BFR group prefix in the first AS in the second AS (carrying the BFR ID of each BFR in the first AS), which enables the device in the second AS to receive multiple routes with the same prefix of the first AS and select one of the routes as the optimal route according to the route optimization method, reducing the complexity of BIER route calculation and ensuring subsequent message forwarding.

Description

Technical Field

[0001] The present application relates to the field of network communication technology, and in particular to a routing announcement method and an electronic device. Background Art

[0002] Bit Index Explicit Replication (BIER) is a new type of multicast technology. Among them, the router that supports BIER capabilities can be called a bit forwarding router (BFR: Bit-ForwardingRouter), and the domain composed of BFR is referred to as the BIER domain. The BFR in the BIER domain is further subdivided into a bit forwarding ingress router (BFIR: Bit-Forwarding Ingress Router), a bit forwarding egress router (BFER: Bit-Forwarding EgressRouter), and an intermediate BFR between BFIR and BFER. The multicast message enters the BIER domain from the BFIR, and is transmitted to at least one BFER via the intermediate BFR, and finally leaves the BIER domain from at least one BFER. Summary of the invention

[0003] The present application provides a routing announcement method and an electronic device to implement BIER routing announcement based on IPv6.

[0004] As an embodiment, the present application is implemented through the following technical solutions:

[0005] A routing announcement method is applied to a first border router ASBR in a first autonomous system AS, the first ASBR and at least one other ASBR in the first AS are both connected to a second AS, the first ASBR and the at least one other ASBR are members of a first forwarding router BFR group, the first ASBR and the at least one other ASBR are configured with a first BFR group prefix in a specified SD, and the first BFR group prefix represents the first BFR group; the method comprises:

[0006] Collect the BFR identification ID of each BFR in the first AS;

[0007] Notify the second AS of a route update UPDATE message; the UPDATE message carries network layer reachability information NLRI and a first bit-indexed explicit replication path attribute BIER Path Attribute; wherein the NLRI includes at least the first BFR group prefix; the BIER Path Attribute includes at least the collected BFR IDs and the first BFR prefix representing the first ASBR, so that at least one ASBR in the second AS that receives the UPDATE message adds a corresponding BIFT forwarding table entry in the bit index forwarding table BIFT, and notifies the BIER route corresponding to the first BFR group prefix in the second AS; the BIFT forwarding table entry includes at least: a BFR neighbor and a forwarding bit mask F-BM, the BFR neighbor is the first BFR prefix, and the F-BM represents the BFR ID corresponding to each BFR reached via the BFR neighbor, wherein the BFR ID represented by the F-BM includes at least the BFR ID collected by the first ASBR in the first AS.

[0008] A routing announcement method, the method is applied to a second border router ASBR in a second autonomous system AS, the second ASBR is connected to a first ASBR in a first AS, at least one other ASBR in the second AS except the second ASBR is also connected to the first AS, the second ASBR and the at least one other ASBR are members of a second forwarding router BFR group, the second ASBR and the at least one other ASBR are configured with a second BFR group prefix in a specified SD, and the second BFR group prefix is ​​used to characterize the second BFR group; the method comprises:

[0009] Receive a routing update UPDATE message announced by the first ASBR in the first AS; the UPDATE message carries at least network layer reachability information NLRI and a newly added BIER Path Attribute, where the NLRI is the first BFR group prefix; the members of the first BFR group corresponding to the first BFR group prefix include the first ASBR, and at least one other ASBR in the first AS connected to the second AS;

[0010] Add a corresponding BIFT forwarding table entry in the bit index forwarding table BIFT; the BIFT forwarding table entry includes at least: a BFR neighbor and a forwarding bit mask F-BM, the BFR neighbor is the first BFR prefix, and F-BM represents the BFR ID corresponding to each BFR reached via the BFR neighbor, wherein the BFR ID represented by F-BM includes at least the BFR ID collected by the first ASBR in the first AS and carried in the BIER Path Attribute;

[0011] The BIER route corresponding to the first BFR group prefix is ​​announced in the second AS, so that when the BFR in the second AS receives multiple BIER routes corresponding to the first BFR group prefix, it selects one of the BIER routes as the optimal route according to the route optimization method.

[0012] An electronic device, comprising: a processor and a machine-readable storage medium;

[0013] The machine-readable storage medium stores machine-executable instructions that can be executed by the processor;

[0014] The processor is used to execute machine executable instructions to implement any of the above method steps.

[0015] Through the above technical solution of the present application, in the present application, each ASBR in the first AS connected to the second AS announces the network reachability information corresponding to the same BFR group prefix to the second AS (carrying BIER Path Attribute, BIER PathAttribute at least includes the BFR ID of each BFR in the first AS). When the ASBR in the second AS receives the network reachability information announced by the ASBR in the first AS, it will continue to announce the BIER route of the same BFR group prefix in the first AS in the second AS (carrying the BFR ID of each BFR in the first AS). This enables the device in the second AS to receive multiple routes with the same prefix of the first AS and select one of the routes as the optimal route according to the route optimization method, reducing the complexity of BIER route calculation and ensuring subsequent message forwarding. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The networking diagram for the cross-AS BIER scenario provided in the embodiment of the present application;

[0017] Figure 2 A flow chart of the method provided in the embodiment of the present application;

[0018] Figure 3 EBGP UPDATE message format diagram provided for an embodiment of the present application;

[0019] Figure 4 This is a diagram of the BGP BIER Path Attribute field structure of an embodiment of the present application;

[0020] Figure 5 This is a BFR ID Range field structure diagram of an embodiment of the present application;

[0021] Figure 6 This is a diagram showing the structure of the BFR-Prefix field of the BFR neighbor in an embodiment of the present application;

[0022] Figure 7 This is a structural diagram of the BIER encapsulation information field of an embodiment of the present application;

[0023] Figure 8 Another flow chart of an embodiment of the present application;

[0024] Fig. 9 A schematic diagram of the network configuration of an embodiment of the present application;

[0025] Fig.10 This is a schematic diagram of notifying external AS BIER information through IGP in an embodiment of the present application;

[0026] Fig.11 A schematic diagram of an external AS BIER information notification via IBGP in an embodiment of the present application;

[0027] Fig.12 A structural diagram of a device provided in an embodiment of the present application;

[0028] Fig.13 Another device structure diagram provided for an embodiment of the present application;

[0029] Fig.14 This is a hardware structure diagram of the device provided in this application. DETAILED DESCRIPTION

[0030] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0031] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0032] In order to enable those skilled in the art to better understand the technical solutions provided by the embodiments of the present application and to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and understandable, the technical terms related to the embodiments of the present application are described below:

[0033] SD (Sub-Domain): indicates a BIER subdomain. There is at least one BIER subdomain in a BIER domain. In the BIER domain, a BFR identifier (ID) is configured for each designated BFR in the BIER subdomain in units of BIER subdomains. Optionally, the designated BFR may be BFIR, BFER, etc., which is not specifically limited in this embodiment.

[0034] BFR prefix (BFR-Prefix): used to characterize BFR. Different BFRs in the same SD are characterized by different BFR prefixes. In specific implementation, the BFR prefix of a BFR can be represented by an IPv4 address or an IPv6 address of the BFR. This embodiment takes an IPv6 address as an example.

[0035] BIER encapsulation type: indicates the BIER encapsulation type supported by BFR, such as MPLS type, Ethernet type, IPv6 type (recorded as BIER6), etc.

[0036] BSL (Bit String Length): indicates the length of the bit string in BIER encapsulation.

[0037] MAX SI (Set Identifier): indicates the maximum number of SIs. SI indicates the ID of the set (Set) to which the bit string in the BIER encapsulation belongs. When the range of the BFR ID exceeds the range of the BSL, multiple Sets are required to represent it, and each Set has a unique ID. For example, if the BFR ID range is 1 to 512 and the BSL is 256, two Sets are required to represent it. SI=0 indicates 1 to 256, and SI=1 indicates 257 to 512.

[0038] Under the premise that BIER is deployed in an AS (the AS with BIER deployed is denoted as AS BIER), when applied to cross-AS BIER scenarios, there are often more than two pairs of AS border routers (ASBR: Autonomous System BorderRouter) connections between two ASs. Figure 1 As shown, there are two pairs of ASBR connections between AS1 and AS2, namely: ASBR1-1 in AS1 is connected to ASBR2-1 in AS2, and ASBR1-2 in AS1 is connected to ASBR2-2 in AS2.

[0039] On the premise that there are at least two pairs of ASBR connections between two ASs, for any of the ASs, at least two ASBRs in the AS that are connected to another AS will collect the BFR IDs of each BFR in the AS, and then carry the collected BFR IDs in the network reachability information corresponding to the BFR-Prefix of the device and publish it to the other AS. Since the BFR-Prefixes of different ASBRs in the same AS are different, when any device in another AS receives the network reachability information published by the above ASBRs, it will consider them to be independent unicast routes based on the different BFR-Prefixes, which will increase the complexity of BIER routing calculations.

[0040] by Figure 1 Taking AS2 in the network shown as an example, ASBR2-1 collects the BFR ID of each BFR in AS2, carries the collected BFR ID in the network reachability information corresponding to the BFR-Prefix of ASBR2-1, and notifies AS1. ASBR2-2 performs similar operations. When ASBR1-1 in AS1 receives the network reachability information corresponding to the BFR-Prefix published by ASBR2-1, it continues to announce it in AS1. Similarly, when ASBR1-2 in AS1 receives the network reachability information corresponding to the BFR-Prefix published by ASBR2-2, it will continue to announce it in AS1. However, since the BFR-Prefix corresponding to the network reachability information published by ASBR2-1 and ASBR2-2 is different, any device in AS1 will regard the network reachability information published by ASBR2-1 and the network reachability information published by ASBR2-2 as two independent unicast routes. For example, when R1-3 in AS1 receives the network reachability information corresponding to the BFR-Prefix of ASBR2-1 and the network reachability information corresponding to the BFR-Prefix of ASBR2-2, it will regard the two network reachability information as two independent unicast routes due to the difference between the BFR-Prefix of ASBR2-1 and the BFR-Prefix of ASBR2-2.

[0041] In fact, although the BFR-Prefix of ASBR2-1 is different from the BFR-Prefix of ASBR2-2, the network reachability information corresponding to the BFR-Prefix of ASBR2-1 and the network reachability information corresponding to the BFR-Prefix of ASBR2-2 both carry the same BFR ID (i.e., the BFR ID of each BFR in AS2), and should not be regarded as independent unicast routes. In the prior art, when there are at least two pairs of ASBR connections between two ASs, the BFR in any AS regards the network reachability information corresponding to different BFR-Prefixes issued by each ASBR in the same AS as an independent unicast route, which will increase the complexity of BIER routing calculation, such as optimizing routes according to BFR IDs, and will also affect subsequent message forwarding.

[0042] In order to solve the above technical problems, the present application provides the following embodiments: Figure 2 The method flow shown:

[0043] See also Figure 2 , Figure 2 A flow chart of a method provided in an embodiment of the present application. The method is applied to a first ASBR in a first AS. In this embodiment, the first ASBR and at least one other ASBR in the first AS are connected to a second AS. It should be noted that the first AS, the first ASBR, and the second AS are only named for the convenience of description and are not intended to be limiting.

[0044] In this embodiment, the first ASBR and at least one other ASBR in the first AS connected to the second AS are members of a BFR group. The BFR group here may also be referred to as a virtual BFR node, and the following description takes the BFR group as an example.

[0045] Optionally, as an embodiment, this embodiment may abstract the ASBRs in the same AS that are connected to the same external AS into a BFR group. Figure 1 Taking the network shown as an example, applied to this embodiment, ASBR1-1 and ASBR1-2 in AS1 that are both connected to AS2 can be abstracted into one BFR group (referred to as BFR group 1), and ASBR2-1 and ASBR2-2 in AS2 that are both connected to AS1 can be abstracted into another BFR group (referred to as BFR group 2), and so on.

[0046] Optionally, as an embodiment, this embodiment may also abstract all ASBRs in the same AS that are connected to various external ASs into a BFR group. Figure 1 Taking the AS1 in the network shown in FIG. 1 as an example, in this embodiment, the ASBR1-1 and ASBR1-2 connected to AS2 in AS1 and the ASBR1-3 connected to AS3 ( Figure 1R1-3 and R1-4 (not shown) are abstracted into a BFR group (denoted as BFR group 1).

[0047] Optionally, this embodiment may also abstract all BFRs whose BFR IDs are not 0 in the same AS into a BFR group. Figure 1 Take AS2 in the network shown as an example. In AS2, the BFR IDs of ASBR2-1, ASBR2-2, R2-3, R2-4, and R2-5 are not 0, so ASBR2-1, ASBR2-2, R2-3, R2-4, and R2-5 can be abstracted as a BFR group. It should be noted that in one embodiment, the BFR ID of a BFR that is usually deployed as a BFIR or BFER is not 0.

[0048] In this embodiment, for each BFR group, members in the BFR group are configured with the same BFR group prefix in the same SD. Optionally, the SD here can be: an SD where all members in the BFR group are located, or an SD to which subsequent routes to be announced belong, etc., which is not specifically limited in this embodiment.

[0049] Optionally, the BFR group prefix is ​​used to characterize the BFR group, and different BFR groups are characterized by different BFR group prefixes. In a specific implementation, the BFR group prefix may be a specified prefix identifier, for example, in the case of an IPv6 network, the BFR group prefix may be a certain IPv6 address, etc., which is not specifically limited in this embodiment.

[0050] Based on the above description, in this embodiment, the first ASBR connected to the second AS in the first AS and at least one other ASBR are configured with the same BFR group prefix in the same designated SD (referred to as the first BFR group prefix). The designated SD may be: an SD where all members of the BFR group are located, or an SD to which subsequent routes to be announced belong, etc. The first BFR group prefix is ​​used to characterize the first BFR group. Taking the application in an IPv6 network as an example, the first BFR group prefix may be an IPv6 address, etc. It should be noted that the first BFR group prefix is ​​only named for the convenience of description and is not used for limitation.

[0051] Based on the above description, Figure 2 As shown, the process may include the following steps:

[0052] Step 201: The first ASBR collects the BFR IDs of the BFRs in the first AS.

[0053] As an embodiment, the BFR IDs collected by the first ASBR may include: BFR IDs deployed as BFIRs in the first AS, and BFR IDs deployed as BFERs in the first AS.

[0054] Optionally, the IGP protocol module or BIER routing management module running locally on the first ASBR can collect the BFR ID of each BFR in the AS through the IGP protocol. When executing to this step 201, the first ASBR can collect the BFR ID of each BFR in the first AS from the IGP protocol module or BIER routing management module running locally, such as the BFR ID deployed as BFIR in the first AS and the BFR ID deployed as BFER.

[0055] Step 202, the first ASBR notifies the second AS of an UPDATE message; the UPDATE message carries at least NLRI and BIERPath Attribute, wherein the NLRI includes at least the first BFR group prefix; the BIER Path Attribute includes at least the collected BFR IDs and the first BFR prefix representing the first ASBR, so that at least one ASBR in the second AS that receives the above UPDATE message adds a corresponding BIFT forwarding table entry in the BIFT and notifies the BIER route corresponding to the first BFR group prefix in the second AS.

[0056] As described in step 202 above, the first ASBR notifies the network reachability information corresponding to the first BFR group prefix where the first ASBR is located through an UPDATE message. Optionally, the UPDATE message in this embodiment can be obtained by extending the External Border Gateway Protocol (EBGP), specifically: an EBGP UPDATE message that newly extends a routing attribute (Path Attribute). Here, the newly extended Path Attribute is the above-mentioned bit-indexed explicit replication path attribute (BIER Path Attribute). In this embodiment, the BIER PathAttribute can be regarded as a newly added Path Attribute in the EBGP UPDATE message, and its specific position in the EBGP UPDATE message is not limited. Figure 3 The following example shows the existing format of the EBGP UPDATE message. The BIERPath Attribute in this embodiment can be Figure 3 A new Path Attribute is added in the Path Attributes shown. In this embodiment, the BIER Path Attribute can adopt the TLV format, which will be described with examples below and will not be repeated here.

[0057] In this embodiment, the above UPDATE message carries NLRI in addition to the BIER Path Attribute. As an embodiment, the NLRI includes at least the first BFR group prefix of the first BFR group and the length of the first BFR group prefix. For example, the NLRI includes at least 2002:2:2F::200 / 128. It can be seen from step 202 and the above NLRI that in this embodiment, members in any BFR group will publish the network reachability information corresponding to the same BFR prefix, that is, the BFR group prefix of the BFR group to which it belongs. In this way, when the BFRs in other ASs subsequently receive the network reachability information corresponding to the same BFR group prefix published by different members of the BFR group, they will no longer consider them as different independent unicast routes due to the same BFR group prefix, and will not perform route calculations separately. This will be explained in detail below and will not be repeated here.

[0058] It should be noted that, in this embodiment, the first BFR prefix carried by the BIER Path Attribute is a prefix configured by the first ASBR in a certain SD, such as the above-mentioned specified SD, for representing the first ASBR, which may be the IPv6 address of the first ASBR. The first BFR prefix here is used to represent the first ASBR, which is different from the above-mentioned first BFR group prefix.

[0059] As described in step 202 above, when the first ASBR notifies the second AS of an UPDATE message, the second ASBR that receives the UPDATE message in the second AS adds the corresponding BIFT forwarding table entry in the BIFT and notifies the BIER route corresponding to the first BFR group prefix in the second AS.

[0060] Optionally, the BIFT forwarding table entry includes at least: a forwarding bit mask (F-BM: Forwarding BitMask) and a BFR neighbor (BFR-NBR: BFR Neighbor). The BFR neighbor is the first BFR prefix mentioned above. The F-BM at least represents the BFR ID corresponding to each BFR reached via the BFR neighbor. Here, the BFR ID represented by the F-BM includes at least the BFR ID collected by the first ASBR in the first AS.

[0061] Optionally, in this embodiment, the BFR ID can be represented by a bit mask of the SI combination corresponding to the BFR ID. For example, in F-BM, the bit corresponding to the BFR ID corresponding to each BFR reached via the above-mentioned BFR neighbor is set to a first value, such as 1, and the remaining bit is set to a second value, such as 0. In F-BM, when the bit is set to the first value, such as 1, it means that the BFR corresponding to the BFR ID represented by the bit can be reached through the BFR neighbor. When the bit is set to 0, it means that the BFR corresponding to the BFR ID represented by the bit cannot be reached through the BFR neighbor. The following will be described with examples, which will not be repeated here.

[0062] In this embodiment, when the second ASBR announces the BIER route corresponding to the first BFR group prefix in the second AS, the above-mentioned BIER Path Attribute will be modified first. Specifically, the first BFR prefix in the above-mentioned BIER Path Attribute will be modified to the second BFR prefix representing the second ASBR, and then the network reachability information corresponding to the first BFR group prefix will be announced in the second AS (carrying the above-mentioned NLRI and the modified BIER Path Attribute, at this time the network reachability information can be referred to as BIER route).

[0063] pass Figure 2 It can be seen from the shown process that in this embodiment, when the first AS and the second AS are connected through at least two pairs of ASBRs, the NLRI of the route update UPDATE message announced by each ASBR in the first AS connected to the second AS is the same (all contain the same BFR group prefix). In this way, when each BFR in the second AS receives multiple routes with the same BFR group prefix from the first AS, the multiple routes are no longer calculated as independent routes, but one of the routes is selected from the multiple routes as the optimal route according to the route optimization method. Compared with the existing method of calculating the multiple routes as independent routes, it obviously reduces the complexity of BIER routing calculation and ensures subsequent message forwarding.

[0064] for example, Figure 1ASBR2-1 and ASBR2-2 in AS2 publish the network reachability information corresponding to the same BFR group prefix (denoted as Group BFR-Prefix2). When ASBR1-1 in AS1 receives the network reachability information corresponding to the first BFR group prefix published by ASBR2-1, it will continue to announce the network reachability information corresponding to the first BFR group prefix in AS1. Similarly, when ASBR1-2 in AS1 receives the network reachability information corresponding to the first BFR group prefix published by ASBR2-2, it will continue to announce the network reachability information corresponding to the first BFR group prefix in AS1. In this way, devices in AS1, such as R1-3, etc., will receive two routes with the same BFR group prefix in AS2. When devices in AS1, such as R1-3, etc., receive two routes with the same BFR group prefix in AS2, they are no longer regarded as independent unicast routes, and route calculations are no longer performed independently. Instead, one of the routes can be selected as the optimal route according to the route optimization method. This obviously reduces the complexity of BIER route calculation and ensures subsequent message forwarding.

[0065] The following is a description of the above BIER Path Attribute:

[0066] As described above, BIER Path Attribute can be a TLV structure. Figure 4 The structure of BIER PathAttribute is shown as an example. Figure 4 The Sub-TLVs field in the BIER Path Attribute structure shown in the example carries the following three newly added sub-sub-TVLs, which are recorded as: first TLV, second TLV, and third TLV.

[0067] 1) First TLV:

[0068] In this embodiment, the first TLV is used to carry the BFR ID collected by the first ASBR in the first AS. Figure 5 As shown, the first TLV at least includes: at least one field pair. Each field pair includes a BFRID field and a BFR ID range field having a corresponding relationship. In this embodiment, the first TLV carries the BFR ID collected by the first ASBR in the first AS through at least one field pair.

[0069] Among them, in each field pair, the parameter carried by the BFR ID Range field is used to represent a BFRID segment with continuous values, and the BFR ID field carries the starting BFR ID of the BFR ID segment. It should be noted that when the first TLV includes more than two field pairs, the starting BFR IDs carried by the BFR ID fields in different field pairs are different. For example, the BFR ID collected by the first ASBR in the first AS is divided into two parts, one part is 1 to 251, and the other part is 260 to 512. Then the first TLV may include: two field pairs, one of which includes: BFR ID field 1_1, BFR ID Range field 1_1; the other field pair includes: BFR ID field 1_2, BFR ID Range field 1_2. Among them, the BFR ID field 1_1 carries the starting value 1 of the BFR ID segment with continuous values, that is, 1 to 251, and the BFR ID Range field 1_1 carries 251, which is used to indicate that the BFR ID segment with continuous values ​​is 1 to 251 (specifically, it can indicate that there are 251 BFR IDs in the BFR ID segment with continuous values, that is, 1 to 251); the BFR ID field 1_2 carries the starting value 260 of the BFR ID segment with continuous values, that is, 260, and the BFR ID Range field 1_2 carries 253, which is used to indicate that the BFR ID segment with continuous values ​​is 260 to 512 (specifically, it can indicate that there are 253 BFR IDs in the BFR ID segment with continuous values, that is, 260 to 512).

[0070] Alternatively, if Figure 5 As shown, in this embodiment, the first TLV also includes a type field and a length field. The Type field and the Length field can be set according to actual conditions, such as the length of the Type field is 2 bytes, the length of the Length field is 2 bytes, etc., which are not specifically limited in this embodiment.

[0071] 2) Second TLV:

[0072] In this embodiment, the second TLV is used to carry the first BFR prefix. Figure 6 As shown, the second TLV may include at least: a BFR-Prefix field. The BFR-Prefix field carries the above-mentioned first BFR prefix, which is used to instruct the BFR that subsequently receives the BGP UPDATE message to use the first BFR prefix as the destination address for forwarding the BIER message to the first ASBR.

[0073] Alternatively, if Figure 6As shown, in this embodiment, the second TLV also includes a Type field and a Length field. The Type field and the Length field can be set according to actual conditions and are not limited here.

[0074] 3) The third TLV:

[0075] In this embodiment, the third TLV is used to indicate the BIER encapsulation information supported by the first ASBR. Figure 7 As shown, the third TLV may include at least: a Type field, a Length field, and a BIER encapsulation information field. Among them, the Type field is used to carry the BIER encapsulation type supported by the first ASBR, such as MPLS encapsulation type, IPv6-based BIER (denoted as BIER6), etc. Optionally, the length of the Type field may be 2 bytes. The Length field can be set according to actual conditions. The Length field is used to indicate the length of the BIER encapsulation information field, 2 bytes for example. The BIER encapsulation information field is used to carry the BIER encapsulation information supported by the first ASBR. As an embodiment, the BIER encapsulation information can be used to assist the second ASBR in determining the table entry identifier of the above-mentioned BIFT forwarding table entry. In an example, the BIER encapsulation information may include at least: MAX SI, BSL, BIFT ID.

[0076] The MAX SI indicates the SI corresponding to the maximum BFR ID in the first AS where the first ASBR is located. Optionally, the MAX SI may occupy 8 bits.

[0077] BSL, which indicates the bit string length in the BIER encapsulation supported by the first ASBR. Optionally, BSL may occupy 4 bits.

[0078] BIFT ID: indicates the identifier of the local BIFT of the first ASBR.

[0079] Optionally, as an embodiment, BIER Path Attribute also carries Figure 4 Here, the SD configuration field carries SD configuration information. As an embodiment, the SD configuration information at least includes: the above-mentioned specified SD and the BFR ID of the first ASBR.

[0080] The method provided in the embodiment of the present application is described below from the perspective of the second ASBR of the second AS:

[0081] See also Figure 8 , Figure 8 Another method flow chart provided in the embodiment of the present application. Figure 8As shown, the process is applied to the second ASBR of the second AS. The second ASBR is connected to the first ASBR in the first AS. In this embodiment, at least one other ASBR in the second AS except the second ASBR is also connected to the first AS, the second ASBR and the at least one other ASBR are members of the second BFR group, and the second ASBR and the at least one other ASBR are configured with a second BFR group prefix in a specified SD, and the second BFR group prefix represents the second BFR group. In this embodiment, the second BFR group prefix can be a specified IPv6 address. It should be noted that the specified SD to which the second BFR group prefix belongs here is the same as or different from the specified SD to which the above-mentioned first BFR group prefix belongs, and this embodiment does not specifically limit it.

[0082] like Figure 8 As shown, the process may include the following steps:

[0083] Step 801, the second ASBR receives the UPDATE message announced by the first ASBR in the first AS; the UPDATE message carries at least NLRI and a newly added BIER Path Attribute, the NLRI includes at least the first BFR group prefix, the members of the first BFR group corresponding to the first BFR group prefix include the first ASBR, and at least one other ASBR in the first AS connected to the second AS.

[0084] In this embodiment, the prefix of the first BFR group is different from the prefix of the second BFR group mentioned above. For example, the prefix of the first BFR group is 2001:1:1A::100 / 128; and the prefix of the second BFR group is 2002:2:2F::200 / 128.

[0085] When the second ASBR receives the UPDATE message notified by the first ASBR in the first AS and finds that the UPDATE message carries the BIER Path Attribute, it considers that the BIER route has been received. Then, step 802 is executed.

[0086] Step 802: The second ASBR adds a corresponding BIFT forwarding table entry in the BIFT. The BIFT forwarding table entry includes at least: a BFR neighbor and an F-BM. The BFR neighbor is the first BFR prefix. The F-BM represents the BFRID corresponding to each BFR reached via the BFR neighbor. The BFR ID represented by the F-BM includes at least the BFR ID collected by the first ASBR in the first AS and carried in the BIER Path Attribute.

[0087] Step 803: The second ASBR announces the BIER route corresponding to the first BFR group prefix in the second AS, so that when the BFR in the second AS receives multiple BIER routes corresponding to the first BFR group prefix, it selects one of the BIER routes as the optimal route according to the route optimization method.

[0088] according to Figure 2 In the process shown, each ASBR in the first AS connected to the second AS will send an UPDATE message carrying the same NLRI (including at least the first BFR group prefix). Figure 8 In the process shown, the ASBR in the second AS connected to the first AS will receive an UPDATE message carrying the same NLRI (including at least the first BFR group prefix), and will also announce the BIER route corresponding to the first BFR group prefix in the second AS. In addition to the ASBRs connected to the first AS, each BFR in the second AS will also announce the BIER route corresponding to the first BFR group prefix in the second AS. Eventually, the BFR in the second AS will receive multiple routes with the same BFR group prefix (i.e., the first BFR group prefix) from the first AS. Because the multiple routes correspond to the same BFR group prefix (i.e., the first BFR group prefix) in the first AS, at this time, the devices in the second AS no longer regard the multiple routes from the first AS as independent unicast routes, nor do they perform independent route calculations. Instead, they select one of them as the optimal route according to the route selection method. This obviously reduces the complexity of the BIER route calculation and also ensures subsequent message forwarding.

[0089] So far, completed Figure 8 The process shown.

[0090] pass Figure 8 The process shown realizes that when the first AS and the second AS are connected through more than two pairs of ASBRs, each ASBR in the second AS connected to the first AS will receive an UPDATE message carrying the same NLRI (including at least the first BFR group prefix) announced by the ASBR in the first AS. Under this premise, each ASBR in the second AS connected to the first AS will announce the BIER route corresponding to the first BFR group prefix carried in the received UPDATE message in the second AS, and eventually the devices in the second AS will receive multiple routes with the same BFR group prefix (i.e., the first BFR group prefix) from the first AS. Because the multiple routes correspond to the same BFR group prefix (i.e., the first BFR group prefix) in the first AS, at this time, the devices in the second AS no longer regard the multiple routes from the first AS as independent unicast routes, nor do they perform independent route calculations, but select one of them as the optimal route according to the route selection method, which obviously reduces the complexity of BIER route calculation and ensures subsequent message forwarding.

[0091] The present application is described below by way of a specific embodiment:

[0092] See also Fig. 9 , Fig. 9 This is a schematic diagram of the network configuration of the embodiment of the present application. Fig. 9 The networking shown is described by taking two ASs, AS_901 and AS_902, as an example, but this is not limiting, and other situations are similar.

[0093] In this embodiment, the BFR ID range in AS_901 is planned to be 1 to 256 (only 1 to 4 are used as examples in this embodiment), and the configuration of each BFR in AS_901 is shown in Table 1:

[0094]

[0095] Table 1

[0096] exist Fig. 9 In the network shown, there are two pairs of connected ASBRs between AS_901 and AS_902, namely: R901_1 as an ASBR in AS_901 is connected to R902_1 as an ASBR in AS_902, and R901_2 as an ASBR in AS_901 is connected to R902_2 as an ASBR in AS_902. Fig. 9 In the example, R901_1 and R901_2 are configured as members of BFR group 1. R901_1 and R901_2 are configured with a BFR group prefix (GBFR-Prefix) in a specified SD (taking SD1 as an example), and the GBFR-Prefix is ​​2001:1:1A::100, which is used to represent BFR group 1. Table 2 shows an example of the GBFR-Prefix configured for R901_1 and R901_2:

[0097]

[0098] Table 2

[0099] In this embodiment, the BFR ID range in AS_902 is planned to be 257-512 (only 260-264 are used in this embodiment), and the configuration of each BFR in AS_902 is shown in Table 3:

[0100]

[0101] Table 3

[0102] exist Fig. 9In the network shown, R902_1 and R902_2, which are ASBRs in AS_902, are configured as members of BFR group_2. R902_1 and R902_2 are configured with a BFR group prefix (GBFR-Prefix) in the same specified SD (taking SD1 as an example). The GBFR-Prefix is ​​2002:2:2F::200, which is used to represent BFR group_2. Table 3 shows the GBFR-Prefix configured for R902_1 and R902_2:

[0103]

[0104] This embodiment takes the notification of BIER information of AS_902 to AS_901 as an example for description as follows:

[0105] like Fig. 9 As shown, in AS_902, R902_1 collects BFR IDs (BFR-IDs for short) in AS_902 from the IGP protocol or BIER routing management module of this device. In this embodiment, the collected BFR-IDs mainly include: 260, 261, 262, 263, then BFR-IDs can be represented by "260, 4", as shown in Table 5 below. Among them, "260" represents the starting value of the BFR ID segment with continuous values ​​(i.e., 260 to 264), and "4" represents the number of BFR IDs in the BFR ID segment with continuous values ​​(i.e., 260 to 264) is 4.

[0106] R902_1 uses an EBGP UPDATE message (referred to as message a1) to announce the network reachability information corresponding to GBFR-Prefix 2002:2:2F::200. Here, message a1 carries NLRI and BIER Path Attribute. Figures 3 to 7 The BGP UPDATE message structure shown in FIG. 1 and the NLRI and BIER Path Attribute carried by message a1 are shown in Table 5:

[0107]

[0108] Table 5

[0109] In Table 5, NBR BFR-prefix:2002:2:2F::1 is the BFR-Prefix of R902_1, which is used as the IPv6 destination address when the neighboring ASBR such as R901_1 that receives message a1 forwards the BIER6 message to R902_1.

[0110] Similarly, similar to R902_1, within AS_902, R902_2 will also collect the BFR ID (BFR-IDs for short) within AS_902 from the IGP protocol or BIER routing management module of this device. The BFR-IDs collected here are described above and will not be repeated here. Afterwards, R902_2 announces the network reachability information corresponding to GBFR-Prefix 2002:2:2F::200 through an EBGP UPDATE message (recorded as message a2). Message a2 carries NLRI and BIER Path Attribute. Based on Figures 3 to 7 The BGP UPDATE message structure shown in Figure 6 shows the NLRI and BIER Path Attribute carried in message a2:

[0111]

[0112] Table 6

[0113] In Table 6, NBR BFR-Prefix:2002:2:2F::2 is the BFR-Prefix of R902_2, which is used as the IPv6 destination address when the neighbor ASBR (R901_2) that receives message a2 forwards the BIER6 message to R902_2.

[0114] R901_1 in AS_901 receives message a1 and finds that message a1 carries the BIER Path Attribute. It then considers that it has received the BIER route and adds the forwarding entry shown in Table 7 below to the BIFT with BIFT ID 2001 (the corresponding BSL / SD / SI are 3 / 1 / 1 respectively):

[0115]

[0116] Table 7

[0117] In Table 7, when a bit in F-BM is set to 1, it means that the BFR corresponding to the BFR ID represented by the bit can be reached through the BFR-NBR in Table 7. On the contrary, when a bit in F-BM is set to 0, it means that the BFR corresponding to the BFR ID represented by the bit cannot be reached through the BFR-NBR in Table 7. For example, in Table 7, F-BM is "1111000", and the "1" on the first bit from the right indicates that the BFR ID is 260, and the "1" on the second bit indicates that the BFR ID is 261, and so on. In addition, R901_1 also modifies the NBR BFR-Prefix in the above BIER Path Attribute from 2002:2:2F::2 to 2001:1:1A::1, and announces the prefix route of the above Group BFR-prefix, i.e. 2002:2:2F::200 / 128, in AS_901, and carries the above modified BIER Path Attribute (at this time, the prefix route can be recorded as a BIER route). After receiving the prefix route of 2002:2:2F::200 / 128 announced by R901_1, other BFRs in AS_901 continue to announce the prefix route of 2002:2:2F::200 / 128 in a similar way to the AS_901 route announcement.

[0118] Similarly, R901_2 of AS_901 receives message a2 and finds that message a2 carries the BIER Path Attribute. It then considers that it has received the BIER route and adds the forwarding entry shown in Table 8 below to the BIFT with BIFT ID 2001 (the corresponding BSL / SD / SI are 3 / 1 / 1 respectively):

[0119]

[0120] Table 8

[0121] The F-BM in Table 8 is similar to that in Table 7 and will not be described in detail. Similarly, R901_2 also announces the prefix route of the above GroupBFR-prefix, i.e., 2002:2:2F::200 / 128, in AS_901 and carries the above modified BIER PathAttribute. After receiving the prefix route of 2002:2:2F::200 / 128 announced by R901_2, other BFRs in AS_901 continue to announce the prefix route of 2002:2:2F::200 / 128 in a similar manner to the route announced by AS_902.

[0122] When the BFR in AS_901 learns two routes with the same prefix of AS_902, namely 2002:2:2F::200 / 128, it selects one of the routes as the optimal route according to the existing route optimization method. Fig. 9 As shown, R901_3 learns two routes with the same prefix of AS_902, namely 2002:2:2F::200 / 128. According to existing route optimization methods such as the shortest path algorithm, the route with the next hop of R901_1 is selected as the optimal route. When the BFR in AS_901 determines the optimal route, it will add the forwarding entry corresponding to the optimal route in BIFT. Fig. 9 As shown in the figure, R901_3 learns two routes with the same prefix, namely 2002:2:2F::200 / 128, and selects the route with the next hop of R901_6 as the optimal route. Then, the forwarding table entries added to the BIFT with BIFT ID of 2001 (corresponding BSL / SD / SI are 3 / 1 / 1 respectively) are shown in Table 9:

[0123]

[0124] Table 9

[0125] It can be seen from the above embodiment that even if AS_901 and AS_902 are connected through two pairs of ASBRs, for any AS (taking AS_902 as an example), the NLRI of the UPDATE message announced by each ASBR connected to AS_901 in AS_902, namely R902_1 and R902_2, is the same, and is the same BFR group prefix. When each ASBR in AS_901, namely R901_1 and R901_2, receives the UPDATE message announced by each ASBR in AS_902, namely R902_1 and R902_2, it will continue to announce the NLRI carried by the above UPDATE message and carry the BIER Path Attribute carried by the above UPDATE message, so that other BFRs in AS_901 will receive multiple routes with the same NLRI of AS_902. When the BFR in AS_901 receives multiple routes with the same NLRI from AS_902, it will select one of the routes as the optimal route according to the route optimization method. This means that the BFR in AS_901 no longer regards the network reachability information announced by the external AS, i.e., each ASBR in AS_902, as independent unicast routes, and no longer performs route calculations independently. Instead, it selects one of them as the optimal route according to the route selection method. This obviously reduces the complexity of BIER route calculation and ensures subsequent message forwarding.

[0126] The above Fig. 9 The illustrated embodiments are described.

[0127] Optionally, in this embodiment, there are many implementation methods for the second ASBR in the above step 803 to announce the BIER route corresponding to the NLRI carried in the UPDATE message in the second AS. The following examples describe two of the implementation methods:

[0128] First way:

[0129] In the first mode, the second ASBR republishes the BIER route of the external AS through IGP in the second AS. Optionally, in the first mode, the second ASBR modifies the first BFR prefix in the above BIER Path Attribute to a second BFR prefix representing the second ASBR, and extends the IGP to introduce the above NLRI and the modified BIER Path Attribute in the IGP and flood it in the second AS (the flooded route can be referred to as the BIER route at this time), so that the BFR in the second AS adds the corresponding BIFT forwarding table entry in the local BIFT. Still with Fig. 9 Taking the network shown as an example, when R901_1 of AS_901 receives the EBGP UPDATE message notified by R902_1 of AS_902, it modifies the BFR prefix of R902_1 in the BIER Path Attribute carried by the EBGP UPDATE message to the BFR prefix of R901_1, and extends the IGP to flood the prefix carried by the EBGP UPDATE message, i.e. 2002:2:2F::200 / 128, and the above-modified BIER PathAttribute in AS_901 through IGP. Similarly, when R901_2 of AS_901 receives the EBGP UPDATE message announced by R902_2 of AS_902, it also modifies the BFR prefix of R902_2 in the BIER Path Attribute carried by the EBGP UPDATE message to the BFR prefix of R901_2, and extends the IGP to flood the prefix carried by the EBGP UPDATE message, i.e. 2002:2:2F::200 / 128, and the modified BIER Path Attribute in AS_901 through IGP. Fig.10 An example is shown of an implementation of route flooding corresponding to 2002:2:2F::200 / 128. In this way, the BFR in AS_901 will learn two routes with the same prefix, 2002:2:2F::200 / 128, in AS_902. When the BFR in AS_901 learns two routes with the same prefix, 2002:2:2F::200 / 128, in AS_902, one of the routes is selected as the optimal route according to the existing route optimization method. For example, Fig. 9As shown, R901_3 learns two routes with the same prefix of AS_902, namely 2002:2:2F::200 / 128. According to the existing route optimization method, such as the shortest path algorithm, the route with the next hop of R901_6 is selected as the optimal route, and the forwarding entry shown in Table 9 is added to the BIFT with BIFT ID 2001 (the corresponding BSL / SD / SI are 3 / 1 / 1 respectively).

[0130] Second way:

[0131] In the second mode, the second ASBR notifies the designated BFR in the second AS of the BIER route of the first BFR group prefix in the external AS through IBGP. Optionally, the second ASBR modifies the first BFR prefix in the above BIER Path Attribute to a second BFR prefix representing the second ASBR, and extends the IBGP protocol, i.e., notifies the designated BFR (the peer of the second ASBR) of the above NLRI and the above modified BIER Path Attribute through the IBGP UPDATE message defined by the extended IBGP protocol, so that the above designated BFR in the second AS adds the corresponding BIFT forwarding entry in the local BIFT. Still in the same way. Fig. 9 Taking the network shown in the figure as an example, when R901_1 of AS_901 receives the EBGP UPDATE message notified by R902_1 of AS_902, it modifies the BFR prefix of R902_1 in the BIER Path Attribute carried in the EBGP UPDATE message to the BFR prefix of R901_1, and extends IBGP to notify the prefix carried in the EBGP UPDATE message, i.e. 2002:2:2F::200 / 128, and the modified BIER Path Attribute to the specified BFR in AS_901 (pre-specified, with Fig. 9 Similarly, when receiving the EBGP UPDATE message notified by R902_2 of AS_902, R901_2 of AS_901 modifies the BFR prefix of R902_2 in the BIER Path Attribute carried in the EBGP UPDATE message to the BFR prefix of R901_2, and extends IBGP to notify the prefix 2002:2:2F::200 / 128 carried in the EBGP UPDATE message and the modified BIER PathAttribute to the specified BFR in AS_901 (pre-specified, with Fig. 9 Take R901_4 shown as an example). Fig.11An example is given of an implementation example of an IBGP UPDATE message announcement. When R901_4 receives the IBGP UPDATE message announced by R901_1 and R901_2, it will learn two routes of the same prefix of AS_902, namely 2002:2:2F::200 / 128, and select one of the routes as the optimal route. For example, according to the shortest path algorithm, the route with the next hop of R901_1 is selected as the optimal route. Then, a forwarding entry is added to the BIFT with BIFT ID 2001 (the corresponding BSL / SD / SI are 3 / 1 / 1 respectively), as shown in Table 10:

[0132]

[0133] Table 10

[0134] The above describes the method provided in the embodiment of the present application. The following describes the device provided in the embodiment of the present application:

[0135] See also Fig.12 , Fig.12 This is a diagram of the structure of the device provided in the embodiment of the present application. The device is applied to the first AS, corresponding to Figure 2 The process shown may specifically include:

[0136] A collecting unit, used to collect BFR IDs of each BFR in the first AS;

[0137] The first notification unit is used to notify the second AS of a routing update UPDATE message; the UPDATE message carries an NLRI and a BIER Path Attribute; wherein the NLRI includes at least the first BFR group prefix; the BIER Path Attribute includes at least the collected BFR IDs and the first BFR prefix representing the first ASBR, so that at least one ASBR in the second AS that receives the UPDATE message adds a corresponding BIFT forwarding table entry in the BIFT and notifies the BIER route corresponding to the first BFR group prefix in the second AS.

[0138] The BIFT forwarding table entry includes at least: a BFR neighbor and an F-BM, the BFR neighbor is the first BFR prefix, and the F-BM represents the BFR ID corresponding to each BFR reached via the BFR neighbor, wherein the BFR ID represented by the F-BM includes at least the BFR ID collected by the first ASBR in the first AS.

[0139] As an embodiment, the BFRs corresponding to the collected BFR IDs are within the designated SD; and / or, the ASBRs in the second AS that receive the UPDATE message are also within the designated SD.

[0140] As an embodiment, the collecting unit collects the BFR ID of each BFR in the AS including:

[0141] Collecting BFR IDs deployed as BFIRs in the first AS; and collecting BFR IDs deployed as BFERs in the first AS.

[0142] As an embodiment, the BIER Path Attribute carries a first TLV; the first TLV includes at least one field pair, and each field pair includes a BFR ID field and a BFR ID Range field having a corresponding relationship;

[0143] The first TLV carries the BFR IDs collected by the first ASBR in the first AS through at least one field pair; wherein, in each field pair, the parameter carried by the BFR ID Range field is used to represent a BFR ID segment with continuous values, and the BFRID field carries the starting BFR ID of the BFR ID segment.

[0144] As an embodiment, the BIER Path Attribute carries a second TLV; the second TLV includes at least a BFR-Prefix field; the BFR-Prefix field carries the first BFR prefix.

[0145] As an embodiment, the BIER Path Attribute also carries: a third TLV; the type field in the third TLV is used to carry the BIER encapsulation type supported by the first ASBR.

[0146] The third TLV also includes: a BIER encapsulation information field, which is used to carry the BIER encapsulation information supported by the first ASBR. Here, the BIER encapsulation information is used to determine the entry identifier of the BIFT forwarding table entry. As an embodiment, the BIER encapsulation information includes at least:

[0147] MAX SI, indicating the SI corresponding to the maximum BFR ID in the first AS;

[0148] BSL, indicates the bit string length in the supported BIER encapsulation;

[0149] BIFT ID, indicating the identifier of the local BIFT.

[0150] As an embodiment, the above BIER Path Attribute also carries: SD configuration field;

[0151] The SD configuration field carries SD configuration information, and the SD configuration information at least includes: the above-mentioned specified SD and the BFR ID of the first ASBR.

[0152] So far, completed Fig.12 The device structure diagram is shown.

[0153] See also Fig.13 , Fig.13 Another device structure diagram provided in an embodiment of the present application. The device is applied to the second ASBR in the second AS. The device corresponds to the above Figure 8 The process shown.

[0154] like Figure 8 As shown, the device may include:

[0155] A receiving unit, used to receive an UPDATE message announced by the first ASBR in the first AS; the UPDATE message carries at least NLRI and a newly added BIER Path Attribute, and the NLRI is the prefix of the first BFR group; the members of the first BFR group corresponding to the first BFR group prefix include the first ASBR, and at least one other ASBR in the first AS connected to the second AS;

[0156] Table entry unit, used to add corresponding BIFT forwarding table entries in BIFT; the BIFT forwarding table entries include at least: BFR neighbors and F-BM, the BFR neighbor is the first BFR prefix, and the F-BM represents the BFRID corresponding to each BFR reached via the BFR neighbor, wherein the BFR ID represented by the F-BM includes at least the BFR ID collected by the first ASBR carried in the BIER Path Attribute in the first AS;

[0157] The second announcement unit is used to announce the BIER route corresponding to the first BFR group prefix in the second AS, so that when the BFR in the second AS receives multiple BIER routes corresponding to the first BFR group prefix, it selects one of the BIER routes as the optimal route according to the route optimization method.

[0158] Optionally, the second notification unit notifies in the second AS that the BIER route corresponding to the NLRI carried by the UPDATE message includes:

[0159] Modify the first BFR prefix in the BIER Path Attribute to a second BFR prefix representing the second ASBR;

[0160] The BIER route corresponding to the first BFR group prefix is ​​republished through the internal gateway protocol IGP in the second AS, or the BIER route corresponding to the first BFR group prefix is ​​announced to the designated BFR in the second AS through the internal gateway border protocol IBGP; the BIER route carries the NLRI and the modified BIER Path Attribute.

[0161] The present application also provides the above Fig.12 or Fig.13 The hardware structure of the device shown. Fig.14 , Fig.14 This is a structural diagram of an electronic device provided in an embodiment of the present application. Fig.14 As shown, the hardware structure may include: a processor and a machine-readable storage medium, the machine-readable storage medium storing machine-executable instructions that can be executed by the processor; the processor is used to execute the machine-executable instructions to implement the method disclosed in the above example of this application.

[0162] Based on the same application concept as the above method, an embodiment of the present application also provides a machine-readable storage medium, on which a number of computer instructions are stored. When the computer instructions are executed by a processor, the method disclosed in the above example of the present application can be implemented.

[0163] Exemplarily, the above-mentioned machine-readable storage medium can be any electronic, magnetic, optical or other physical storage device that can contain or store information, such as executable instructions, data, etc. For example, the machine-readable storage medium can be: RAM (Radom Access Memory), volatile memory, non-volatile memory, flash memory, storage drive (such as hard disk drive), solid state drive, any type of storage disk (such as CD, DVD, etc.), or similar storage medium, or a combination thereof.

[0164] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, which may be in the form of a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email transceiver, a game console, a tablet computer, a wearable device or a combination of any of these devices.

[0165] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0166] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the embodiments of the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0167] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0168] Moreover, these computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0169] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0170] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

[0171] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A routing advertisement method, characterized in that: The method is applied to a first autonomous system border router ASBR in a first autonomous system AS, the first ASBR and at least one other ASBR in the first AS are both connected to a second AS, the first ASBR and the at least one other ASBR are members of a first forwarding router BFR group, the first ASBR and the at least one other ASBR are configured with a first BFR group prefix in a designated subdomain SD, and the first BFR group prefix represents the first BFR group; the method comprises: Collect the BFR identification ID of each BFR in the first AS; Notify the second AS of a route update UPDATE message; the UPDATE message carries network layer reachability information NLRI and a bit-indexed explicit replication path attribute BIER Path Attribute; wherein the NLRI includes at least the first BFR group prefix; the BIER Path Attribute includes at least the collected BFR IDs and the first BFR prefix representing the first ASBR, so that at least one ASBR in the second AS that receives the UPDATE message adds a corresponding BIFT forwarding table entry in the bit index forwarding table BIFT, and notifies the BIER route corresponding to the first BFR group prefix in the second AS; the BIFT forwarding table entry includes at least: a BFR neighbor and a forwarding bit mask F-BM, the BFR neighbor is the first BFR prefix, and the F-BM at least represents the BFR ID corresponding to each BFR reached via the BFR neighbor, wherein the BFRID represented by the F-BM includes at least the BFRID collected by the first ASBR in the first AS.

2. The method according to claim 1, characterized in that The BFRs corresponding to the collected BFRIDs are within the specified SD; and / or, Each ASBR in the second AS that receives the UPDATE message is also in the designated SD.

3. The method according to claim 1, characterized in that The collecting of the BFR identification IDs of the BFRs in the first AS includes: Collecting the BFR IDs of the BFIRs deployed as bit forwarding ingress routers in the first AS; and, Collect the BFR IDs of the BFERs deployed as bit forwarding egress routers in the first AS.

4. The method according to claim 1, characterized in that: The BIER Path Attribute carries a first TLV; the first TLV includes at least one field pair, and each field pair includes a BFR ID field and a BFRID range Range field having a corresponding relationship; The first TLV carries the BFR ID collected by the first ASBR in the first AS through at least one field pair; wherein, in each field pair, the parameter carried by the BFR ID Range field is used to represent a BFRID segment with continuous values, and the BFRID field carries the starting BFR ID of the BFRID segment.

5. The method according to claim 1, characterized in that The BIER Path Attribute carries a second TLV; the second TLV includes at least a BFR-Prefix field; The BFR-Prefix field carries the first BFR prefix.

6. The method according to claim 1, characterized in that The BIER Path Attribute also carries: a third TLV; The type field in the third TLV is used to carry the BIER encapsulation type supported by the first ASBR; The third TLV also includes: a BIER encapsulation information field, wherein the BIER encapsulation information field is used to carry the BIER encapsulation information supported by the first ASBR; The BIER encapsulation information is used to determine the entry identifier of the BIFT forwarding table entry.

7. The method according to any one of claims 1 to 6, characterized in that: The BIER Path Attribute also carries: SD configuration field; The SD configuration field carries SD configuration information, and the SD configuration information at least includes: the designated SD and the BFRID of the first ASBR.

8. A routing advertisement method, characterized in that: The method is applied to a second border router ASBR in a second autonomous system AS, the second ASBR is connected to a first ASBR in a first AS, at least one other ASBR in the second AS except the second ASBR is also connected to the first AS, the second ASBR and the at least one other ASBR are members of a second bit forwarding router BFR group, the second ASBR and the at least one other ASBR are configured with a second BFR group prefix in a specified SD, and the second BFR group prefix is ​​used to characterize the second BFR group; the method comprises: Receive a routing update UPDATE message announced by the first ASBR in the first AS; the UPDATE message carries at least network layer reachability information NLRI and a newly added BIER Path Attribute, where the NLRI is the first BFR group prefix; the members of the first BFR group corresponding to the first BFR group prefix include the first ASBR, and at least one other ASBR in the first AS connected to the second AS; Add a corresponding BIFT forwarding table entry in the bit index forwarding table BIFT; the BIFT forwarding table entry includes at least: a BFR neighbor and a forwarding bit mask F-BM, the BFR neighbor is the first BFR prefix, and F-BM represents the BFRID corresponding to each BFR reached via the BFR neighbor, wherein the BFR ID represented by F-BM includes at least the BFR ID collected by the first ASBR in the first AS and carried in the BIER Path Attribute; The BIER route corresponding to the first BFR group prefix is ​​announced in the second AS, so that when the BFR in the second AS receives multiple BIER routes corresponding to the first BFR group prefix, it selects one of the BIER routes as the optimal route according to the route optimization method.

9. The method according to claim 8, characterized in that The BIER route corresponding to the NLRI carried in the UPDATE message announced in the second AS includes: Modify the first BFR prefix in the BIER Path Attribute to a second BFR prefix representing the second ASBR; The BIER route corresponding to the first BFR group prefix is ​​republished through the internal gateway protocol IGP in the second AS, or the BIER route corresponding to the first BFR group prefix is ​​announced to the designated BFR in the second AS through the internal gateway border protocol IBGP; the BIER route carries the NLRI and the modified BIER Path Attribute.

10. An electronic device, characterized in that: The electronic device includes: a processor and a machine-readable storage medium; The machine-readable storage medium stores machine-executable instructions that can be executed by the processor; The processor is used to execute machine executable instructions to implement the method steps of any one of claims 1-9.

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