Method and system for synchronizing a standby route distributor in a distributed routing platform

• US 20040100969A1
• Filed: 04/25/2003
• Published: 05/27/2004
• Est. Priority Date: 11/22/2002
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Inventors: Iyer, Sreeram P., Sankar, Ramkumar, Vaidya, Sachchidanand D.
• Granted Patent: US 7,230,914 B2
• Time in Patent Office: Days
• US Class Current: 370/395.31
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/58 Association of routers
• CPC Class Codes: H04L 45/583 Stackable routers
• CPC Class Codes: H04L 45/60 Router architectures
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database

Abstract

A system and method is directed to synchronizing a standby route distributor in a distributed routing platform. A route distributor is configured to operate as an active route distributor. Another route distributor is configured to operate as a standby route distributor. The standby and active route distributor may reside in the same or a different distributed routing platform. A slave route distributor communicates a route to the active route distributor. The active route distributor may update its routing tables with the route. The active route distributor forwards the route to the standby route distributor to enable their routing tables to be substantially synchronized. The standby route distributor distributes the route to the slave route distributors, where the route enables an update to another routing table. In the event of a switchover, the standby route distributor resynchronizes its routing tables and may distribute route information to each slave route distributor.

Claims

1. A method for synchronizing a routing table, comprising:

(a) receiving a route;

(b) updating an active routing table associated with an active route distributor with the route;

(b) forwarding the route to a standby route distributor;

(c) updating a standby routing table associated with the standby route distributor, wherein at least a portion of the standby routing table and the active routing table are substantially synchronized; and

(d) employing the standby distributor to distribute the route to a slave route distributor, wherein the slave route distributor is enabled to update a slave routing table associated with the slave route distributor.

2. The method of claim 1, wherein receiving the route further comprises receiving the route from a routing protocol that comprises at least one of a static routing protocol, default routing protocol, Routing Information Protocols (RIPs), Open Shortest Path First (OSPF), Enhanced Interior Gateway Routing Protocol (EIGRP), ISIS, and Border Gateway Protocol (BGP).

3. The method of claim 1, wherein the method is performed within nodes on a distributed routing platform.

4. The method of claim 1, wherein forwarding the route to the standby route distributor, further comprises associating an operation with the route.

5. The method of claim 4, wherein an operation further comprises at least one of an add, modify, initialize, and delete operation.

6. The method of claim 1, wherein distributing the route further comprises distributing the route through an inter node communication.

7. The method of claim 1, wherein employing the standby route distributor to distribute the route further comprises:

updating a route state associated with the route; and

providing an acknowledgement from the standby route distributor to the active route distributor.

8. The method of claim 1, further comprising:

receiving another route by the standby route distributor from a routing protocol associated with the standby route distributor;

updating the standby routing table; and

updating a route state associated with the other route.

9. The method of claim 1, further comprising:

if an acknowledgement is received by the active router distributor, marking the forwarded route as clean by the active route distributor.

10. The method of claim 1, further comprising, marking the route by the standby route distributor based on a comparison of an active state and a standby state associated with the route.

11. The method of claim 10, wherein marking the route further comprising:

if the active state is substantially different from the standby state, identifying the route as dirty; and

if the active state is substantially the same as the standby state, identifying the route as clean.

12. The method of claim 1, further comprising:

if the active route distributor is unavailable, resynchronizing the route on the standby route distributor;

distributing the resynchronized route to at least one slave route distributor; and

assuming an action of the active route distributor by the standby route distributor.

13. A method of synchronizing a routing table, comprising:

(a) employing a standby route distributor to receive a route;

(b) adding the received route to a routing table associated with the standby route distributor; and

(c) if the route is from an active route distributor, employing the standby route distributor to perform actions, including;

(i) distributing the route to at least one slave route distributor, wherein the slave route distributor is enabled to update a slave routing table associated with the slave route distributor;

(ii) updating an active state associated with the route; and

(iii) providing a response to the active route distributor, wherein the response indicates that at least a portion of the routing table associated with the standby route distributor is substantially synchronized with another routing table that is associated with the active route distributor.

14. The method of claim 13, further comprising:

(a) if the route is from a routing protocol associated with the standby route distributor, updating a standby state associated with the route; and

(b) marking the route based on a comparison of the active state and standby state associated with the route.

15. The method of claim 14, wherein marking the route further comprises:

if the active state and the standby state associated with the route are substantially the same, identifying the route as a clean route; and

if the active state and the standby state associated with the route are substantially different, identifying the route as a dirty route.

16. The method of claim 13, further comprising:

if the active route distributor is unavailable, resynchronizing the route on the standby route distributor;

distributing the resynchronized route to at least one slave route distributor; and

assuming an action associated with the active route distributor by the standby route distributor.

17. The method of claim 16, wherein resynchronizing the route further comprises determining an operation associated with the route based in part on a comparison between a standby state and the active state associated with the route.

18. A router for updating a routing table, comprising:

(a) a slave route distributor on a first node that is configured to receive a route associated with a routing protocol associated with the slave route distributor;

(b) an active route distributor on a second node that is configured to perform actions, including;

(i) receiving the route from the slave route distributor;

(ii) updating an active routing table associated with the active route distributor; and

(c) a standby route distributor on a third node that is configured to perform actions, including;

(i) receiving the route from the active route distributor;

(ii) updating a standby routing table associated with the standby route distributor, wherein at least a portion of the standby routing table and the active routing table are substantially synchronized; and

(iii) distributing the route to another slave route distributor, wherein the other slave route distributor is configured to update another routing table associated with the other slave route distributor.

19. The router of claim 18, wherein the router is a distributed routing platform.

20. The router of claim 18, wherein if the active route distributor is unavailable, the standby route distributor is configured to perform actions, further comprising:

(a) resynchronizing a route operation in the standby routing table associated with the standby route distributor;

(b) distributing the route to each slave route distributor; and

(c) assuming the actions of the unavailable active route distributor.

21. The router of claim 20, wherein resynchronizing the route operation further comprises a means for determining an action based in part on an active state and a standby state associated with the route.

22. The router of claim 20, wherein the route operation further comprises at least one of an initialize, add, modify, and delete operation.

23. A system for updating a routing table, comprising:

(a) an active route distributor that is configured to perform actions, including;

(i) receiving a route;

(ii) updating an active routing table associated with the active route distributor with the route; and

(b) a standby route distributor that is configured to perform actions, including;

(i) receiving the route from the active route distributor;

(ii) updating a standby routing table associated with the standby route distributor, wherein at least a portion of the standby routing table and the active routing table are substantially synchronized; and

(iii) distributing the route to a slave route distributor, wherein the slave route distributor is configured to update a slave routing table associated with the slave route distributor.

24. The system of claim 23, wherein the active route distributor, and standby route distributor each reside on a different node in a distributed routing platform.

25. The system of claim 23, wherein the active route distributor and standby route distributor each reside in a different distributed routing platform.

26. An apparatus for updating a routing table, comprising:

(a) a means for receiving a route from a slave route distributor, and updating an active routing table with the route, wherein the active routing table is associated with an active route distributor; and

(b) a means for employing a standby route distributor to receive the route from the active route distributor, wherein the standby route distributor distributes the route to another slave route distributor, and updates a standby routing table associated with the standby route distributor, and wherein at least a portion of the standby routing table and the active routing table are substantially synchronized.