WO2012024948A1

WO2012024948A1 - Method and apparatus for integrating routing

Info

Publication number: WO2012024948A1
Application number: PCT/CN2011/074318
Authority: WO
Inventors: 史亮
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-08-27
Filing date: 2011-05-19
Publication date: 2012-03-01
Also published as: CN101931590A

Abstract

The present invention discloses a method and an apparatus for integrating routing, and in the method and apparatus, partial forwarding information and an outlet index in the routing table can be acquired; a platform software table is searched according to the outlet index so as to acquire the outlet and encapsulation information, and the obtained information in the routing table is integrated with the obtained information in the platform software table to acquire the complete forwarding information. The method and apparatus can obviously improve the forwarding efficiency without secondary hardware table searching or secondary routing, ensure that two-level forwarding can be realized on the device which does not support repeated table searching, and reduce the device cost on the premise of providing the same function.

Description

Route integration method and device

The present invention relates to the field of communications, and in particular, to a route integration method and apparatus. Background technique

With the continuous development of the Internet and intranet, Layer 3 VPN (Visual-Private-Network, Virtual Private Network), ECMP (Equal-Cost Multi-Path), FRR (Fast ReRoute) Various technologies are becoming more and more widely used. The demand for two-stage ecmp/frr networking is also becoming more common. As shown in Figure 1: The Layer 3 VPN network, the remote destination CE (Custom Edge Router) performs dual-homing, and the remote PE (Provider Edge Router) devices back up to reach the primary. The public network of the PE device is load balanced. The local PE needs to support multi-level ecmp/frr route forwarding. The existing technology mainly relies on searching the hardware forwarding table multiple times. First, the routing table is checked according to the destination IP address. If the egress is ecmp or frr, the first-level egress index is obtained, and the hardware table is checked according to the index; The indicated exit is still ecmp or frr, which means that it is multi-level nested, obtain the second-level index, and then check the ecmp/frr hardware table to obtain the real export information for encapsulation and forwarding.

The above technical content has the following drawbacks:

1. The device that does not support the secondary lookup table or the secondary route cannot implement the routing and forwarding of the above nested networking.

2. Supporting multiple tables or routing devices, the hardware cost is high, and the hardware table needs to be searched multiple times. Obviously, the forwarding efficiency is low. Summary of the invention

In view of the above, the main object of the present invention is to provide a route integration method and apparatus, which can ensure two-level forwarding on a device that does not support multiple table lookups, and improve forwarding efficiency.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

A route integration method, the method comprising:

Obtaining part of the forwarding information and the egress index in the routing table, searching the platform software table according to the egress index, and obtaining the export and encapsulation information;

The complete forwarding information is integrated according to the information in the routing table and the platform software table.

The searching for the platform software table is implemented by a loop search based on a routing table, and the process of the loop search includes:

According to the index relationship from the primary index to the multi-level index, the index of each level under the primary index is searched step by step, and the platform software table is obtained accordingly.

The integration of complete forwarding information includes:

The egress and encapsulation information is obtained from the platform software table obtained in each loop search, and the partial forwarding information obtained from the routing table is combined, and finally the complete forwarding information is integrated.

The egress index is implemented based on an established index relationship, and the index relationship includes at least one of the following:

Address resolution protocol arp to fast reroute / equivalent multipath frr / ecmp / routing index relationship; frr to routing index relationship; ecmp to routing index relationship; public network frr to virtual private network vpn ecmp / vpn fir ό index Relationship; index relationship of public network ecmp to vpn ecmp/vpn frr.

The method further includes routing update processing for providing routing update information that can be referenced for integrating the complete forwarding information;

The routing update is caused by a change in the next hop arp, or caused by a change in the frr group, or caused by a change in the ecmp group.

A route integration device, the device includes a routing table processing unit, and a platform software table processing list Yuan, integrated unit; among them,

The routing table processing unit is configured to obtain partial forwarding information and an egress index in the routing table. The platform software table processing unit is configured to obtain an egress index obtained by the routing table processing unit, and search for platform software according to the routing software Table, obtaining export and package information;

The integration unit is configured to obtain forwarding information acquired by the routing table processing unit and a platform software table found by the platform software table processing unit, and integrate the information according to the obtained routing table and the platform software table. Complete forwarding information.

The searching of the platform software table processing unit for the platform software table is implemented by performing a loop search based on the routing table; and the platform software table processing unit is used to: when searching the platform software table in a loop:

When the integration unit integrates the complete forwarding information, it is used for:

Index relationship of arp to frr/ecmp/route; index relationship of frr to route; index relationship of ecmp to route; index relationship of public network frr to vpn ecmp/vpn frr; index relationship of public network ecmp to vpn ecmp/vpn frr .

The apparatus further includes a routing update unit, configured to: provide the integration unit with routing update information that can be used for reference;

The routing update is caused by a change in the next hop arp, or caused by a change in the fa group, or caused by a change in the ecmp group.

The method and device of the invention no longer need to check the hardware table or the secondary route twice, and the forwarding efficiency Significantly improved; and can ensure that two-level forwarding can be implemented on devices that do not support multiple look-up tables, reducing equipment costs while providing the same functionality. DRAWINGS

Figure 1 is a schematic diagram of a two-stage ecmp/frr networking application scenario;

2 is a flowchart of two-stage ecmp/frr routing integration according to an embodiment of the present invention;

3 is a schematic diagram of a reference relationship between an address resolution protocol (arp) and a frr/ecmp route according to an embodiment of the present invention;

4 is a flowchart of a route update caused by a change of a next hop ar according to an embodiment of the present invention; FIG. 5 is a flowchart of a route update caused by a variation of a frr group according to an embodiment of the present invention; FIG. 6 is an ecmp according to an embodiment of the present invention; Flowchart update flow chart caused by group change; FIG. 1 is a schematic diagram of a route integration process according to an embodiment of the present invention;

FIG. 8 is a diagram of a route integration apparatus according to an embodiment of the present invention. detailed description

In general, the platform software can be used to deliver the routing table, and the platform software table can be queried, and the complete export information can be integrated according to the routing table and the platform software table, and the integrated export information is sent to the driver once to write the hardware. In the subsequent application, the hardware only needs to perform a table lookup process for the hardware table to complete the two-stage ecmp/frr forwarding.

The above operation ideas can include the following steps:

1) The routing table is delivered, and part of the forwarding information and the exit index are obtained.

2) Find the platform software table according to the export index to obtain the export and package information.

3) Integrate the complete forwarding information according to the information in the routing table and the platform software table.

It should be noted that the egress index includes an ecmp index or an frr index. Also, if the exit index is not found in the platform software table, it ends directly. The complete forwarding information usually includes: destination ip, mask, vpn id, physical outbound interface, outbound interface index, next hop ip address, The destination media access controls mac, out tags, and so on.

In actual application, the specific route integration process is shown in Figure 2. The process includes the following steps:

Step 201: The upper layer protocol sends a routing table to add or trigger a route update.

Step 202: Determine whether the route exit type is a normal next hop, and if yes, enter the step

203; Otherwise, proceed to step 204.

Step 203: Check the platform software table according to the next hop ip and the layer 3 interface index to obtain the destination mac and the physical outgoing port.

Step 204: Find the platform software table according to the export frr index or the ecmp index, and determine whether the search is successful. If successful, go to step 205; otherwise, return the failure and end the process.

Step 205: Set the value of i to zero.

Step 206: Determine whether i is less than m, if not, proceed to step 208; otherwise, proceed to step 207.

Step 207: Add complete forwarding information such as route prefix information and exit information to the driver. Specifically, the route prefix information includes the destination ip, the mask, the vpn id, and the like. The egress information includes the next hop ip, the physical egress port, the destination mac, the outbound interface index, and the next hop vpn id.

Step 208: Determine whether there is a secondary index for the exit of the i th next hop. If yes, go to step 210; otherwise, go to step 209.

Step 209: Check the platform software table according to the ip address of the i-th next hop and the layer 3 interface index to obtain the destination mac and the physical egress port.

Step 210: Find the platform software table according to the export frr index or the ecmp index, and determine whether the search is successful. If the search is successful, go to step 211; otherwise, return the failure and end the process.

Step 211: Set the value of j to zero.

Step 212: Determine whether j is less than n, if not, proceed to step 213; otherwise, proceed to step 215. Step 213: Check the platform software table according to the ip address of the jth next hop and the layer 3 interface index to obtain the destination mac and the physical outgoing port.

Step 214: Accumulate j, return to step 212.

Step 215: Accumulate i, return to step 206.

It can be seen from the above process that the search for the platform software table is implemented by a cyclic lookup based on the routing table, such as: according to the index relationship from the primary index to the multi-level index (such as the secondary index), the hierarchical search is performed under the primary index. The index of each level (such as all secondary indexes), in order to obtain the platform software table. Based on the above-mentioned loop search mode, when the complete forwarding information is integrated, the egress and encapsulation information can be obtained from the platform software table obtained in each previous loop, and combined with the partial forwarding information obtained from the routing table. The final integration of the complete forwarding information.

There is an index relationship between the indexes in the above process. The reference relationship between arp, frr/ecmp, and routing can be combined. Figure 3 illustrates the index relationship. Referring to Figure 3, the normal next hop arp change will change the route that references it or the ecmp/frr that references it. The arp change needs to trigger the relevant frr/ecmp and route update. Similarly, the frr/ecmp change will refer to it. If the vpn frr, vpn ecm, or route changes, the related vpn frr, vpn ecm, and route update must be triggered. The vpn frr or vpn ecmp change will change the route exit that references it, and the related route update needs to be triggered. Therefore, it is necessary to establish an index relationship with the opposite direction of the reference relationship: index relationship of arp to frr/ecmp/route; index relationship of frr to route; index relationship of ecmp to route; index relationship of public network fir to vpn ecmp/vpn frr ; public network ecm to vpn ecmp / vpn frr index relationship.

The update relationship between the route, the next hop arp, and the ecmp/frr group can be described in combination with the above index.

Specifically, the protocol can not perceive all the next-hop _ar p changes required by the current routing module integrated response arp change, and triggers associated routing update the driver. The route update process caused by the normal next hop change is shown in Figure 4. The process shown in Figure 4 includes the following steps: Step 401: The protocol sends an arp add, delete, or update operation.

Step 402: Determine whether the subnet route referring to the arp can be found according to the index relationship. If yes, go to step 403; otherwise, go to step 404.

Step 403: Specifically processing according to the operation type. For example: If it is an arp add or update operation, the complete exit information and the found route prefix information are integrated and written. If the arp delete operation is performed, you can set the subnet route exit to the CPU and wait for the arp information to complete before re-integrating the subnet route exit.

Step 404: Determine whether the ecmp group referring to the aip can be found according to the index relationship. If yes, go to step 405; otherwise, go to step 406.

Step 405: Perform a route update process according to ecmp cable.

Step 406: Determine whether the frr group referring to the arp can be found according to the index relationship. If it can be found, go to step 407; otherwise, end the process.

Step 407: Perform a route update process according to the frr index.

The routing update process caused by the change of the frr group is shown in Figure 5. The process shown in Figure 5 includes the following steps:

Step 501: Determine whether it is a frr group update operation, and if yes, go to step 502; otherwise, go to step 510.

Step 502: Determine whether the platform frr software entry can be found according to the frr index. If it can be found, go to step 503; otherwise, end the process.

Step 503: Determine whether vpn frr or vpn ecmp that references the frr group can be found according to the index relationship. If it can be found, go to step 504; otherwise, go to step 507.

Step 504: Determine whether the platform software entry can be found according to the vpn frr/vpn ecmp index. If it can be found, go to step 505; otherwise, go to step 507.

Step 505: Determine whether the route a referring to the vpn fir or the vpn ecmp can be found according to the index relationship. If it can be found, go to step 506; otherwise, go to step 507. Step 506: Integrate the complete forwarding information, and update the route a reference vpn frr/vpn ecmp.

Step 507: Determine whether the route b referring to the frr group can be found according to the index relationship, and proceed to step 508 when it can be found.

Step 508: If it is a frr update or add operation, integrate the complete route b information and update the driver; if it is a frr delete operation, temporarily set the exit of the route b to the send cpu, and update the driver. End this process.

Step 510: Determine whether to add an operation to the frr group, if yes, go to step 503; otherwise, go to step 520.

Step 520: Determine whether the frr group delete operation, if yes, proceed to step 507; otherwise, end the process.

The route update process caused by the change of the ecmp group is shown in Figure 6. The process shown in Figure 6 includes the following steps:

Step 601: Determine whether the Ecmp group update operation is performed. If yes, go to step 602; otherwise, go to step 610.

Step 602: Determine whether the platform Ecmp software entry can be found according to the Ecmp index. If it can be found, go to step 603; otherwise, end the process.

Step 603: Determine whether vpn fir or vpn ecmp that references the Ecmp group can be found according to the index relationship. If it can be found, go to step 604; otherwise, go to step 607.

Step 604: Determine whether the platform software entry can be found according to the vpn frr/vpn ecm index. If it can be found, go to step 605; otherwise, go to step 607.

Step 605: Determine whether the route a referring to vpn frr or vpn ecmp can be found according to the index relationship. If it can be found, go to step 606; otherwise, go to step 607.

Step 606: Integrate the complete route a information and update the driver.

Step 607: Determine whether the route b that references the Ecmp group can be found according to the index relationship. And when it can be found, it proceeds to step 608.

Step 608: If it is an Ecmp update or add operation, integrate the information of the complete route b and update the driver; if it is an Ecmp delete operation, temporarily set the exit of the route b to the send cpu, and update the driver. End this process.

Step 610: Determine whether to add an operation to the Ecmp group. If yes, go to step 603; otherwise, go to step 620.

Step 620: Determine whether the Ecmp group delete operation is performed. If yes, go to step 607; otherwise, end the process.

According to the above process description, the operation idea of the route integration of the present invention can be represented as shown in FIG. 7. Referring to FIG. 7, FIG. 7 is a schematic diagram of a route integration process according to an embodiment of the present invention, where the process includes the following steps:

Step 710: The routing table is delivered, and part of the forwarding information and the egress index are obtained.

Step 720: Find the platform software table according to the egress index, and obtain the export and encapsulation information. Step 730: Integrate the complete forwarding information according to the information in the routing table and the platform software table. In order to ensure that the above processes and operation ideas can be smoothly implemented, the settings shown in Figure 8 can be performed. Referring to FIG. 8, FIG. 8 is a diagram of a route integration apparatus according to an embodiment of the present invention. The apparatus includes an associated routing table processing unit, a platform software table processing unit, and an integration unit, and may further include a route update unit connected to the integration unit.

In a specific application, the routing table processing unit can issue a routing table and obtain part of the forwarding information and the egress index; the platform software table processing unit can obtain the egress index obtained by the routing table processing unit, and search the platform accordingly. Software table, get export and package information. The merging unit can obtain the forwarding information obtained by the routing table processing unit and the platform software table found by the platform software table processing unit, and integrate the complete forwarding information according to the obtained routing table and the information in the platform software table.

In addition, the route update unit is capable of performing route update processing as shown in FIGS. 4 to 6, and The processing result is notified to the integration unit, and the integration unit provides routing update information that can be used for reference when integrating the complete forwarding information.

It should be noted that, for any unit in each unit shown in FIG. 8, as long as the unit needs to apply a reference relationship between arp and frr/ecmp routes, the reference relationship can be maintained. The specific operations that can be implemented in each unit shown in FIG. 8 have been described in detail in the foregoing process, and are not described herein again. In addition, for the traditional primary ecmp/frr networking or common networking, the foregoing process is equally applicable.

In summary, the two-stage ecmp/frr routing integration technique of the present invention has the following beneficial effects as compared with the prior art, whether it is a method or a device:

1. It is no longer necessary to check the hardware table or secondary route twice, and the forwarding efficiency is obviously improved.

2. Ensure that two-level forwarding can be implemented on devices that do not support multiple table lookups, reducing device costs while providing the same functionality.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included. Within the scope of protection of the present invention.

Claims

Claim

A route integration method, characterized in that the method comprises:

The method according to claim 1, wherein the searching for the platform software table is implemented by performing a loop search based on a routing table, and the process of the loop searching includes: following the index from the primary index to the multi-level index The index relationship, step by step to find the index of each level under the first level index, and obtain the platform software table accordingly.

3. The method according to claim 2, wherein the integrating the complete forwarding information comprises:

The method according to any one of claims 1 to 3, wherein the export index is implemented by an established index relationship, and the index relationship includes at least one of the following:

Index resolution protocol arp to fast reroute / equivalent multipath frr / ecmp / routing index relationship; frr to routing index relationship; ecmp to routing index relationship; public network fir to virtual private network vpn ecmp / vpn frr index Relationship; index relationship of public network ecmp to vpn ecmp/vpn frr.

The method according to any one of claims 1 to 3, characterized in that the method further comprises routing update processing for providing routing update information that can be used for reference for integrating the complete forwarding information;

A routing integration device, comprising: a routing table processing unit, a platform software table processing unit, and an integration unit; wherein The routing table processing unit is configured to obtain partial forwarding information and an egress index in the routing table. The platform software table processing unit is configured to obtain an egress index obtained by the routing table processing unit, and search for platform software according to the routing software Table, obtaining export and package information;

The apparatus according to claim 6, wherein the searching by the platform software table processing unit for the platform software table is implemented by performing a loop search based on a routing table; the platform software table processing unit is in a loop Used when looking up the platform software table:

The device according to claim 7, wherein when the integration unit integrates the complete forwarding information, it is used for:

The device according to any one of claims 6 to 8, wherein the export index is implemented by an established index relationship, and the index relationship includes at least one of the following:

The device according to any one of claims 6 to 8, characterized in that the device further comprises a routing update unit, configured to: provide the integration unit with route update information that can be used for reference;

The routing update is caused by a change in the next megabyte, or by a change in the frr group, or by a change in the ecmp group.