WO2008003253A1

WO2008003253A1 - The method and system of routing calculation for the directly connected broadcast link

Info

Publication number: WO2008003253A1
Application number: PCT/CN2007/070178
Authority: WO
Inventors: Jiangping Zhang; Chao Fu
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-06-26
Filing date: 2007-06-26
Publication date: 2008-01-10
Also published as: CN100591040C; CN101043432A

Abstract

A method and system of routing calculation for the directly connected broadcast link are provided. The said method obtains the address prefix to be calculated routing from the intra-area-prefix-LSA. When the said address prefix to be calculated routing is in the directly connected broadcast link and is not included in the local configured address prefixes, the said method obtains the local link address of the router attached by the said address prefix to be calculated routing, and assigns the next hop address of the routing for the said address prefix to be calculated routing to be the said local link address. By employing the said method and system, the forwarding of message can be efficiently guided when the corresponding IPv6 intra-area-prefix is different to the local intra-area-prefix.

Description

Route calculation method and system on direct broadcast link

This application claims the priority of the Chinese patent application filed on June 26, 2006, the Chinese Patent Office, Application No. 200610061334.5, entitled "A Calculation Method and System for Routing on Direct Broadcast Links" The entire contents are incorporated herein by reference.

Technical field

The present invention relates to the field of network technologies, and in particular, to a method and system for calculating a route on a direct broadcast link.

Background technique

With the development of network communication technology, OSPF (Open Shortest Path First) routing protocol has become the most widely used routing protocol in the network. In the definition of an OSPF routing protocol, a routing domain or an AS (Autonomous System) can be divided into several areas. In OSPF, a collection of networks or routers grouped together according to certain OSPF routing rules is called an area (AREA). The routes in the OSPF routing domain can be classified into two types according to the destination address and the source address of the IP packet. When the destination is in the same area as the source address, it is called intra-area routing, and the destination and source address are in the same area. When different areas are even in different ASs, they are called inter-domain routes. The OSPF routing protocol uses the link state algorithm, that is, each router collects and generates link state information around itself, and forms an LSA (Link State Advertisement) to propagate in the area, so that each router in the area has The same LSA, that is, all the LSAs in the area. All the LSA groups are called link state databases, which are used to describe the network topology information of the area. Each router passes the SPF (Shortest Pass First) according to all received LSAs. The path-first algorithm calculates the routing information and generates a routing table for guiding packet forwarding.

Different types of LSAs identify different types of network topologies. According to the priority, the route types can be classified into: intra-area routing, inter-area routing, autonomous system external type 1 routing, autonomous system external type 2 routing, and priority decreasing. When the router receives a new LSA, it will be placed in the respective link state database according to the LSA category, and then the topology of the link state database is changed and recalculated according to the SPF algorithm. To update the routing table, the routing table can reflect changes in link state information. When the intranet network changes, all routes are recalculated.

OSPFv3 (Open Shortest Path First v3) is a network protocol that supports IPv6 (Internet Protocol Version 6). A routing protocol that supports broadcast link state information. As shown in Figure 1, the IPV6 forwarding layer downloads OSPFv3 routing information. When the packet passes through the IPV6 forwarding layer, the SPF algorithm calculates the shortest path of the packet to the destination and forwards the packet. The routing information includes a distance to the destination address, a local outbound interface, and a next f-mega address.

The direct connection route on the broadcast link is shown in Figure 2, where RTA (Router A, Router A) 21, RTB22 and RTC23 share the broadcast link through interfaces la, lb and Ic. The interface of the RTB and the RTC interface Ic are connected to the interface of the RTA. For the RTA, the RTA is connected to the RTB and the RTC through the interface la. The IPv6 network segment route configured on the interface is a direct route.

The routing information of OSPFv3 is obtained by using the SPF algorithm, and the routing information of the relevant address is obtained by calculating the LSA. On the broadcast network, a network LSA is generated by a DR (Designed Router), and an intra-area prefix LSA referenced by the network LSA is generated. The physical topology in FIG. 2 can be abstracted into the logical topology in FIG. . The network LSA is used to describe which routers exist on the network. The intra-area prefix LSA is used to describe the prefix information connected to the router. Within the area, each router must notify all other routers of the prefix information it is connected to by the intra-area prefix LS A . The intra-area prefix LSA refers to the network LSA, that is, in the process of calculation, only the routing information of the network LS A needs to be obtained, and the intra-area prefix LS A of the network LS A can inherit the routing information of the network LSA. , that is, the routing information of the two is the same. As shown in Figure 3, the routing information of the RTA to the network LSA is: The distance from the RTA to the network LSA is equal to the distance of the OSPFv3 configured on the interface la; the outgoing interface of the RTA is the interface la; the next hop is the local configured on the interface la. The link address is either empty. The intra-area prefix configured on the RTA to the RTC interface Ic is the same as the routing information of the RTA to the network LSA.

For the RTA, if the IPv6 prefix configured on the RTC interface Ic is the same as the IPv6 prefix configured on the RTA interface la, the ND (Neighbor Discovery) protocol of the IPv6 layer functions to find the peer RTC. The one-hop address, that is, the local link address on the RTC interface Ic, guides the packet forwarding; but if the prefix Ic in the IPv6 area configured on the RTC interface Ic is different from the prefix la in the IPv6 area configured on the RTA interface la, the ND protocol The RTA cannot find the IPv6 address on the Ic, and the result is as shown in Figure 4. The outgoing interface of the RTA is the interface la, and the next hop is the local link address configured on the interface la or empty. The ND protocol is used to discover the IPv6 address of the IPv6 area. The RTA cannot guide the packet forwarding. On the broadcast link, If the next hop address is the local link address or is empty, the IPv6 forwarding layer cannot forward packets.

For example, the IPv6 prefix configuration of the direct broadcast link is as follows:

RTA: The global unicast address is 2001 :1 :1 :1 : 48, and the link-local address is FE80::RTA;

RTB: The global unicast address is 2002 : 2:2:2 ::/48, and the link-local address is FE80::RTB;

RTC: The global unicast address is 2003:3:3:3::/48, and the link-local address is FE80::RTC;

According to the existing route calculation method on the direct broadcast link, when calculating the routing information of the prefix LSA in the RTA to the IPv6 area, the routing information of the network LSA is obtained first, and then the area prefix LSA of the network LSA is referred to. And inheriting the routing information of the network LSA, the route from the RTA to the IPv6 prefix 2003:3:3::/48 is 2003:3:3::/48, and the routing information of the RTA to the network LSA is: RTA to the network LSA The distance is equal to 1; the outgoing interface of the RTA is interface la; the next hop is FE80::RTA or is empty. Therefore, the obtained next hop information cannot be forwarded to the prefix address where 2003:3:3:48 is located.

That is, in the case where the prefix in the IPv6 area of the peer end is different from the prefix in the local area, the packet forwarding cannot be guided.

Summary of the invention

The embodiment of the invention provides a method and a system for calculating a route on a direct-connected broadcast link, so that the "3" message can be correctly forwarded if the IPv6 prefix of the peer end and the local prefix are different.

The method for calculating a route on a direct-connected broadcast link provided by the embodiment of the present invention includes: obtaining an address prefix of a route to be calculated in an intra-area prefix LSA;

If the address prefix of the route to be calculated is on the direct broadcast link and is not included in the locally configured address prefix, obtain the link address of the router to which the address prefix of the route to be calculated is attached as The next hop of the route that calculates the address prefix of the route.

The route calculation system of the directly connected broadcast link provided by the embodiment of the present invention includes: a prefix extraction unit, configured to acquire an address prefix of a route to be calculated in an intra-area prefix LSA; and a first determining unit, configured to determine the Whether the address prefix of the route to be calculated is directly connected to the broadcast link;

a second determining unit, configured to determine whether the locally configured address prefix includes the address prefix of the to-be-calculated route;

The route calculation unit, the judgment result of the first judgment unit and the second judgment unit is: When the address prefix of the route to be calculated is on the directly connected broadcast link and is not included in the locally configured address prefix, obtain the link address of the router to which the address prefix of the route to be calculated is attached as the to-be-addressed The next hop of the route that calculates the address prefix of the route.

The route calculation system of the direct-connected broadcast link provided by the embodiment of the present invention includes: a prefix extracting unit that takes a prefix of the calculated route;

a first determining unit, determining whether the prefix of the to-be-calculated route is on the direct-connected broadcast link, and determining, by the second determining unit, whether the locally configured prefix includes the prefix of the to-be-calculated route; the information obtaining unit obtains the peer end The local link address is used as the next hop of the route to the prefix of the route to be calculated, and the routing information obtained by obtaining the prefix of the route to be calculated is written into the routing table.

In the embodiment of the present invention, when the IPv6 prefix of the peer end is different from the local prefix, the network LSA is directly connected to the local end, and the local link address of the peer end is obtained as the next hop of the route of the prefix. Guided "^ text forwarding.

DRAWINGS

1 is a schematic diagram of packet forwarding in the prior art;

2 is a schematic diagram of routing on a direct broadcast link in the prior art;

3 is a logical topology diagram of a OSPFv3 protocol for a broadcast link in the prior art;

4 is a schematic diagram of a next hop calculated by the OSPFv3 protocol in the prior art;

5 is a schematic diagram of a next hop of a direct-connected broadcast link according to an embodiment of the present invention;

6 is a flowchart of a method for calculating a route on a direct-connected broadcast link according to an embodiment of the present invention; FIG. 7 is a schematic diagram of an IPv6 prefix configuration of a direct-connected broadcast link according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a computing system for routing on a direct broadcast link according to an embodiment of the present invention; FIG.

FIG. 9 is another schematic structural diagram of a computing system for routing on a direct broadcast link according to an embodiment of the present invention.

detailed description

In the embodiment of the present invention, when the reference LSA is the network LSA and the network LSA is directly connected to the local LSA, it is checked whether the address prefix configured on the router interface to which the prefix is attached in the area is configured. If configured, the current network LSA is used as the reference LSA, and the routing information of the reference network LSA is inherited; if not configured, the corresponding configuration is found. The neighboring router of the address prefix obtains the next hop information of the route of the address prefix by referring to the next hop information of the neighboring router LSA.

As shown in Figure 5, RTA51, RTB52 and RTC53 share the broadcast link through interfaces la, lb and Ic. The interfaces of the RTB and the RTC interface Ic are connected to the interface of the RTA. For the RTA, the RTA is connected to the RTB and the RTC through the interface la. The IPv6 network segment route configured on the interface is a direct route.

For the RTA, when calculating the routing information of the prefix LSA in the IPv6 area, when the reference LSA is the network LSA, and the referenced network LSA is directly connected to the RTA, that is, the RTA is directly connected to the broadcast link, but the RTA is not configured. The address prefix of the router to which the prefix is attached in the IPv6 area, and the IPv6 address prefix configured on the RTC interface Ic is the same as the address prefix in the prefix LSA of the IPv6 area, and the RTC is configured in the corresponding LSA in the IPv6 area. A neighboring router with an address prefix, so that the next hop information of the route prefix included in the prefix LSA in the IPv6 area is obtained by referring to the next hop information of the LSC router LSA.

As shown in FIG. 6, when the route calculation method provided by the embodiment of the present invention calculates the routing information of the prefix LSA in the area, the method includes the following steps:

S600: Take the first address prefix in the prefix LSA in the IPv6 area, and perform step S601;

S601: Determine whether the reference LSA is a network LSA;

If the reference LSA is a network LSA, step S602 is performed, and if the reference LSA is not a network LSA, step S603 is performed;

S602: Check whether the referenced network LSA is directly connected to the local device, that is, the router where the address prefix is taken in step 600 is directly connected to the broadcast link. If the referenced network LSA is directly connected to the local device, step S604 is performed. If the referenced network LSA is not directly connected to the local, step S603 is performed;

Step S603: The routing information of the address prefix inherits the routing information of the reference LSA, and then, step S609 is performed;

Step S604: Take the first child node of the network LSA, that is, the ID of the router LSA, and find the LSA corresponding to the router in the database according to the ID information, and check whether the address prefix is the same as the address prefix configured on the interface of the router. ;

If the address prefix is the same as the address prefix configured on the interface of the router, go to the step. S605, if the address prefix is not the same as the address prefix configured on the router interface, step S606 is performed;

S605: The current network LSA is used as the reference LSA, and the routing information of the reference router LSA node is inherited, and step S603 is performed;

S606: The child node where the address prefix is located is determined to be empty. If the child node where the address prefix is located is empty, step S608 is performed. If the child node where the address prefix is located is not empty, step S607 is performed. ;

S607: The distance from the router LSA to the network LSA is obtained from the router LSA, and the router LSA of the address prefix is used as the reference LSA, and the next hop information of the router LSA is obtained, and step S609 is performed;

S608: giving an error message, performing step S609;

S609: Obtain the routing information of the address prefix and write the routing information to the routing table, and perform step S610. The routing information of the address prefix includes: a local outbound interface, a next hop information, a cost value, and the like; S610: take the intra-area prefix LSA The next address prefix, step S611;

S611: determining whether the next address prefix is empty;

If the next address prefix is empty, the process ends; if the next address prefix is not empty, then step S601 is returned.

The calculation process of the route in the embodiment of the present invention is further described in detail below with reference to FIG. 7:

The IPv6 prefix configuration of the direct broadcast link shown in Figure 7 is as follows:

RTA71: The global unicast address is 2001 :1 :1 :1 : 48, and the link-local address is FE80::RTA;

RTB72: The global unicast address is 2002:2:2:2: 48, and the local link address is FE80::RTB;

RTC73: The global unicast address is 2003:3:3:3:48, and the local link address is FE80::RTC; if the route calculation method on the direct-connected broadcast link provided by the embodiment of the present invention is used, the RTA is calculated. When the routing information of the LSA is prefixed in the IPv6 area, the RTA to IPv6 address prefix is first taken, that is, 2003:3:3::/48, and then the reference LSA is determined to be the network LSA, and the reference network LSA and the local router RTA are used. After the direct connection, the address prefix of the RTA to IPv6 is the same as the address prefix configured on the RTA interface la of the router. It can be seen that the address prefix of the router from RTA to IPv6 is 2003:3:3:48. The address prefix configured on the router RTA interface la is 2001:1:1::/48, that is, the address prefix of the router RTA to IPv6 is connected to the router RTA. If the address prefix configured on the LA is different, the neighboring router RTC with the address prefix of the RTA to IPv6 is 2003:3:3:748. The RTC is the router corresponding to the RTA to IPv6 address prefix, and then judges. Whether the neighboring router RTC of the address prefix 2003:3:3::/48 is empty, and if it is determined to be empty, the next hop information of the route of the address prefix is obtained by referring to the next hop information of the RTC LSA, FE80::RTC, and the route from RTA to IPv6 address prefix 2003:3:3::/48 is 2003 :3 :3: :/48 , then the distance from the network LSA to the network LSA is equal to 1, RTA The outgoing interface is Ia. In this way, the router RTA can use the obtained next hop information FE80::RTC to guide the packet forwarding to the prefix address where 2003:3:3::/48 is located. The present invention also provides a computing system for routing directly on a broadcast link. Referring to FIG. 8 is a structural block diagram of the system of the embodiment of the present invention:

In this embodiment, a prefix extracting unit 81, a first judging unit 82, a second judging unit 83, and an information obtaining unit 84 are included.

The prefix extracting unit 81 takes the prefix of the to-be-calculated route from the intra-area prefix LSA; the first determining unit 82 determines whether the prefix of the to-be-calculated route is on the direct-connected broadcast link;

The second determining unit 83 determines whether the locally configured prefix includes the prefix of the to-be-calculated route;

The prefix obtained by the information obtaining unit 84 on the route to be calculated is on the direct broadcast link, and the locally configured prefix does not include the prefix of the route to be calculated, and the local link address of the peer is obtained as the Calculating the next hop of the route of the prefix of the route, and writing the routing information of the prefix of the route to be calculated into the routing table.

The first determining unit 82 includes a reference LSA determining unit 821 and a network LSA determining unit 822;

The reference LSA determining unit 821 determines whether the reference LSA of the prefix LSA of the route to be calculated in the area is a network LSA;

The network LSA determining unit 822 determines whether the network LSA is locally connected.

If the reference LSA of the prefix LSA to be calculated in the area is a network LSA, and the network LSA is locally connected, the prefix of the to-be-calculated route is on the direct broadcast link.

The second determining unit 83 includes a prefix determining unit 831, a routing information obtaining unit 832, and Subnode determination unit 833;

The prefix determining unit 831 determines whether the locally configured prefix includes the prefix of the to-be-calculated route;

The routing information obtaining unit 832 uses the network LSA as the reference LSA, and obtains the local link address of the peer by using the neighbor discovery protocol, as the next hop of the route to the prefix of the to-be-calculated route, and obtains the to-be-calculated route. Routing information for the prefix;

The child node determining unit 833 determines whether the child node where the prefix of the route to be calculated is located, that is, whether the router LSA node is empty.

The information obtaining unit 84 includes a next hop address obtaining unit 841 and a routing distance obtaining unit

842;

The next hop address obtaining unit 841 finds a router with the prefix of the route to be calculated from the router included in the network LSA, and obtains the next hop address by using the LSA of the router as the reference LSA. The next hop address is the local link address of the peer.

The route distance obtaining unit 842 obtains the distance of the network LSA as the distance to the route of the prefix.

The next hop address obtaining unit 841 includes a link searching unit 8411 and a link address obtaining unit 8412;

The link searching unit 8411 finds a link LSA with the same address prefix and the prefix of the to-be-calculated route in the link LSA to which the router belongs.

The link address obtaining unit 8412 obtains the link-local address of the link LSA as the link-local link address.

The prefix extracting unit 81 takes the first address prefix from the intra-area prefix LSA to be calculated, and the reference LSA determining unit 821 determines whether the reference LSA is a network LSA. If the reference LSA is not a network LSA, the routing information obtaining unit 832 inherits the reference. The routing information of the LSA obtains the routing information of the address prefix and writes the routing information to the routing table;

If the reference LSA is a network LSA, the network LSA determining unit 822 checks whether the referenced network LSA is directly connected to the local, that is, whether the router where the address prefix is located is directly connected to the broadcast link, if the referenced network LSA is not locally Directly, the routing information obtaining unit 832 inherits the routing information of the reference LSA, obtains routing information of the address prefix, and writes the routing information to the routing table; If the referenced network LSA is directly connected to the local, the prefix determining unit 831 takes the child node of the first network LSA, that is, the router LSA node, and checks whether the address prefix is the same as the address prefix configured on the router interface, if the The address prefix is the same as the address prefix configured on the interface of the router. The routing information obtaining unit 832 uses the current network LSA as the reference LSA, inherits the routing information of the reference LSA node, and obtains the routing information of the address prefix and writes the routing information to the routing table.

If the address prefix is different from the address prefix configured on the interface of the router, the child node determining unit 833 takes the child node where the address prefix is located, that is, the router LSA node, and determines whether it is empty, if the child of the address prefix is located. If the node is empty, the error information is given, and the routing information obtaining unit 832 obtains the routing information of the address prefix and writes the routing information to the routing table;

If the child node where the address prefix is located is not empty, the route distance obtaining unit 842 obtains the distance from the node where the address prefix is located to the LSA node of the router from the network LSA, and the link searching unit 8411 is on the link to which the router belongs. In the LSA, the link LSA with the same address prefix as the prefix of the to-be-calculated route is found, and the link address obtaining unit 8412 obtains the link-local address of the link LSA as the local link address of the peer, and obtains the address prefix. Routing information and write to the routing table.

It can be seen that, in the embodiment of the system of the present invention, if the IPv6 address prefix and the local address prefix of the peer end are different, the reference network LSA is directly connected to the local device, so as to obtain the local link address of the peer end as the route to be calculated. The next hop of the route of the address prefix, so that the router can guide the packet to forward correctly according to the routing information.

Referring again to FIG. 9, another structural block diagram of the system of the embodiment of the present invention is shown:

In this embodiment, a prefix extracting unit 91, a first judging unit 92, a second judging unit 93, and a route calculating unit 94 are included. among them,

The prefix extracting unit 91 is configured to obtain an address prefix of the route to be calculated in the intra-area prefix LSA. The first determining unit 92 determines whether the address prefix of the to-be-calculated route is on the direct broadcast link. The second determining unit 93 determines the local Whether the prefix of the route to be calculated is included in the configured prefix; the judgment result of the information obtaining unit 94 in the first determining unit 92 and the second determining unit 93 is: the address prefix of the route to be calculated is on the direct broadcast link When not included in the locally configured address prefix, the local link address of the router to which the address prefix of the route to be calculated is attached is obtained as the next hop of the route to the prefix of the route to be calculated.

The first determining unit 92 includes a reference LSA determining unit 921 and a network LSA determining unit 922; The reference LSA determining unit 921 is configured to determine whether the reference LSA of the address prefix LSA of the route to be calculated in the area is a network LSA; and in the case where the reference LSA determining unit 921 determines that the reference LSA is a network LSA, the network LSA determining unit 922 It is determined whether the network LSA is connected to the local. If the reference LSA of the address prefix LSA of the route to be calculated in the area is a network LSA, and the network LSA is locally connected, it may be determined that the address prefix of the to-be-calculated route is on the direct broadcast link.

The second judging unit 93 includes a prefix judging unit 931 and a child node judging unit 933. The prefix determining unit 931 is configured to determine whether the locally configured address prefix includes the address prefix of the to-be-calculated route. If the locally configured address prefix does not include the address prefix of the to-be-calculated route, the child node needs to be determined. The unit 933 determines whether the child node where the address prefix of the route to be calculated is located, that is, whether the router LSA node is empty. If it is empty, it indicates that the node does not exist. In this case, the error information can be given by the child node judging unit 933.

The route calculation unit 94 includes a next hop address obtaining unit 941 and a route distance obtaining unit 942. The next hop address obtaining unit 941 finds the router with the address prefix of the route to be calculated from the router included in the network LSA, and obtains the next hop address by using the LSA of the router as the reference LSA. The next hop address is used as the link-local address of the router to which the address prefix of the route to be calculated is attached. The route distance obtaining unit 942 obtains the distance of the network LSA as the distance to the route of the router to which the address prefix of the route to be calculated is attached.

The next hop address obtaining unit 941 includes a link finding unit 9411 and a link address obtaining unit 9412. The link searching unit 9411 finds the link LSA with the same address prefix and the same address prefix as the route to be calculated in the link LSA to which the router belongs. The link address obtaining unit 9412 obtains the local chain of the link LSA. The way address is the link address of the router to which the address prefix of the route to be calculated is attached.

In the case that the prefix determining unit 931 determines that the locally configured address prefix includes the address prefix of the to-be-calculated route, the local link address of the router to which the address prefix of the to-be-calculated route is attached may be obtained by using the neighbor discovery protocol. The next hop of the route to the address prefix of the route to be calculated is obtained, and the routing information of the address prefix of the route to be calculated is obtained. To this end, the routing information obtaining unit 95 connected to the prefix determining unit 931 can also be provided in the embodiment of the system of the present invention to implement the above functions. The working process of each unit in the system of the embodiment of the present invention is as follows: The prefix extracting unit 91 takes the first address prefix from the intra-area prefix LSA to be calculated, and the reference LSA determining unit 921 determines whether the reference LSA is a network LSA. If the reference LSA is not the network LSA, the routing information obtaining unit 95 inherits the routing information of the reference LSA, obtains the routing information of the address prefix, and writes the routing information to the routing table;

If the reference LSA is a network LSA, the network LSA determining unit 922 checks whether the referenced network LSA is directly connected to the local, that is, whether the router where the address prefix is located is directly connected to the broadcast link. If the referenced network LSA is not directly connected to the local area, the routing information obtaining unit 95 inherits the routing information of the reference LSA, obtains the routing information of the address prefix, and writes the routing information to the routing table;

If the referenced network LSA is directly connected to the local, the prefix determining unit 931 takes the child node of the first network LSA, that is, the router LSA node, and checks whether the address prefix is the same as the address prefix configured on the router interface. If the address prefix is the same as the address prefix configured on the interface of the router, the routing information obtaining unit 95 uses the current network LSA as the reference LSA, inherits the routing information of the reference LSA node, obtains the routing information of the address prefix, and writes the route. Table

If the address prefix is different from the address prefix configured on the interface of the router, the child node determining unit 933 takes the child node where the address prefix is located, that is, whether the router LSA node is empty. If the child node where the address prefix is located is empty, giving an error message, the routing information obtaining unit 95 obtains the routing information of the address prefix;

If the child node where the address prefix is located is not empty, the route distance obtaining unit 942 obtains the distance from the node where the address prefix is located to the router LSA node from the network LSA, and the link searching unit 9411 is on the link to which the router belongs. In the LSA, the link LSA with the same address prefix as the prefix of the to-be-calculated route is found, and the link address obtaining unit 9412 obtains the link-local address of the link LSA as the local link address of the peer, and obtains the address prefix. Routing information.

In addition, in the system embodiment of the present invention, the routing information writing unit 96 may be further configured to write routing information of the prefix of the to-be-calculated route obtained by the route calculating unit 94 and/or the routing information obtaining unit 95. table.

It can be seen that, in the embodiment of the system of the present invention, if the IPv6 address prefix and the local address prefix of the peer end are different, the reference network LSA is directly connected to the local device, so as to obtain the local link address of the peer end as the route to be calculated. The next hop of the route of the address prefix, so that the router can guide the packet to forward correctly according to the routing information. The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed by the present invention. Alternatives are intended to be covered by the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

Rights request

A method for calculating a route on a direct broadcast link, which is characterized by comprising:

Obtain an address prefix of the route to be calculated in the prefix link state advertisement in the area;

2. The method according to claim 1, wherein: determining whether the address prefix of the route to be calculated is on a direct broadcast link according to the following steps: if the reference link state advertisement is a network link state advertisement And the network link state advertisement is directly connected to the local, and then determining that the address prefix of the to-be-calculated route is on the direct broadcast link.

3. The method according to claim 2, wherein the following step is performed to determine whether the network link status advertisement is directly connected to the local:

The router identity included in the network link state advertisement is found, and if there is a local router identity, the network link state advertisement and local direct connection.

The method according to claim 2, wherein the obtaining the link-local address of the router to which the address prefix of the route to be calculated is attached is the next route to the address prefix of the route to be calculated. The steps to jump include:

And finding, from the router included in the network link state advertisement, a router that is equipped with the address prefix of the route to be calculated;

The link state advertisement of the router is used as a reference link state advertisement to obtain its next hop address; the next hop address is used as the local link address of the router to which the address prefix of the route to be calculated is attached.

The method according to claim 4, wherein the step of advertising the link state of the router as a reference link state advertisement, and obtaining the next hop address comprises:

In the link state advertisement of the link to which the router belongs, the link state advertisement of the link whose address prefix is the same as the address prefix of the to-be-calculated route is found; the link address of the router to which the prefix is attached.

The method according to claim 2, wherein the method further comprises the step of: obtaining a distance of the network link state advertisement as a distance to a route of the address prefix of the route to be calculated.

The method according to claim 2, wherein the method further comprises the step of: if the reference link state advertisement is a network link state advertisement, and the address prefix of the to-be-calculated route is in direct broadcast The link information is included in the locally configured address prefix, and the network link state advertisement is used as a reference link state advertisement to obtain routing information of the address prefix of the to-be-calculated route.

The method according to claim 7, wherein the step of using the network link state advertisement as a reference link state advertisement to obtain routing information of the address prefix of the to-be-calculated route includes:

The local link address of the peer is obtained through the neighbor discovery protocol as the next hop of the route to the address prefix of the route to be calculated.

A route calculation system for a direct-connected broadcast link, comprising:

a prefix extracting unit, configured to acquire an address prefix of the route to be calculated in the prefix link state advertisement in the area;

a first determining unit, configured to determine whether an address prefix of the to-be-calculated route is on a direct broadcast link;

The routing calculation unit, when the judgment result of the first determining unit and the second determining unit is: when the address prefix of the to-be-calculated route is on the direct broadcast link and is not included in the locally configured address prefix, Obtaining the link-local address of the router to which the address prefix of the route to be calculated is attached as the next hop of the route to the address prefix of the route to be calculated.

The system according to claim 9, wherein the first determining unit comprises: a reference link state advertisement determining unit, configured to determine an address prefix link network link state advertisement of the to-be-calculated route And a determining unit, configured to determine, in the case that the reference link state advertisement determining unit determines that the reference link state advertisement is a network link state advertisement, whether the network link state advertisement is locally connected.

The system according to claim 9, wherein the second determining unit comprises: a prefix determining unit, configured to determine whether the locally configured address prefix includes the address prefix of the route to be calculated;

The child node determining unit is configured to determine whether the child node where the address prefix of the route to be calculated is located is empty.

The system according to claim 9, wherein the route calculation unit comprises: a next hop address obtaining unit, and finding, from the router included in the network link state advertisement, that the route to be calculated is The router of the address prefix advertises the link state of the router as a reference link state advertisement, obtains its next hop address, and the next hop address is the local link address of the peer end; the route distance obtaining unit obtains The distance of the network link state advertisement is the distance from the route of the router to which the address prefix of the route to be calculated is attached.

The system according to claim 12, wherein the next hop address obtaining unit comprises:

a link-finding unit, in a link state advertisement of a link to which the router belongs, find a link state advertisement of a link in which an address prefix is the same as an address prefix of the to-be-calculated route;

The link address obtaining unit obtains the link address of the link state advertisement of the link as the link address of the router to which the address prefix of the route to be calculated is attached.

The system according to any one of claims 9 to 13, wherein the system further comprises:

a routing information obtaining unit, where the prefix determining unit determines that the locally configured address prefix includes the address prefix of the to-be-calculated route, obtaining a link-local address of the peer by using a neighbor discovery protocol, as the route to be calculated The next hop of the route of the address prefix obtains the routing information of the address prefix of the route to be calculated.

The system according to claim 14, wherein the system further comprises: a routing information writing unit, configured to calculate the to-be-calculated obtained by the routing computing unit and/or the routing information obtaining unit The routing information of the prefix of the route is written to the routing table.

16. A route calculation system for a direct-connected broadcast link, comprising:

a prefix extraction unit that takes a prefix for calculating a route;

a first determining unit, determining whether the prefix of the to-be-calculated route is on a direct broadcast link; a second determining unit, determining whether the locally configured prefix includes the prefix of the to-be-calculated route; and obtaining, by the information obtaining unit, the local link address of the peer as the next hop of the route to the prefix of the to-be-calculated route, The routing information of the prefix of the route to be calculated is written into the routing table.

The system according to claim 16, wherein the first determining unit comprises: a reference link state advertisement determining unit, determining whether a reference link state advertisement of the prefix link state advertisement of the to-be-calculated route is advertised Is the network link status notification;

The network link state advertisement determining unit determines whether the network link state advertisement is locally connected.

The system according to claim 16, wherein the second determining unit comprises: a prefix determining unit, determining whether the locally configured prefix includes the prefix of the to-be-calculated route; The network link state advertisement is a reference link state advertisement, and the local link address of the peer end is obtained by the neighbor discovery protocol, and the next hop of the route to the prefix of the to-be-calculated route is obtained, and the prefix of the to-be-calculated route is obtained. Routing information.

The system according to claim 16, wherein the information obtaining unit comprises: a next hop address obtaining unit, and finding, from the router included in the network link state advertisement, the route to be calculated The router of the prefix is advertised with the link state of the router as the reference link state advertisement, and the next hop address is obtained, and the next hop address is the local link address of the peer.

The system according to claim 19, wherein the next hop address obtaining unit comprises:

a link-finding unit, in the link state advertisement of the link to which the router belongs, finds a link state advertisement of the link whose address prefix is the same as the prefix of the to-be-calculated route;

The link address obtaining unit obtains the link-local address of the link state advertisement of the link as the link-local link address.

The system according to claim 19, wherein the information obtaining unit further comprises:

The route distance obtaining unit obtains the distance of the network link state advertisement as the distance to the route of the prefix.