Selective passive address resolution learning

• US 20080144634A1
• Filed: 12/15/2006
• Published: 06/19/2008
• Est. Priority Date: 12/15/2006
• Status: Abandoned Application

• Current Assignee: Check Point Software Technologies Incorporated (Check Point Software Technologies Limited)
• Original Assignee: Nokia Corporation
• Inventors: Rashiyamany, Giritharan, Nguyen, Tuyen, Chamarajanagar, Raveendra, Kimble, Scott, Hunt, Peter
• Application Number:
  US11/639,422
• Publication Number:
  US 20080144634A1
• Time in Patent Office: Days
• US Class Current: 370/397
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/247 using M:N active or standby paths
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/586 of virtual routers
• CPC Class Codes: H04L 61/103 across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP]
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

Selective passive address resolution protocol (ARP) learning can provide a passive mechanism to synchronize link layer adjacency information among network elements. Selective passive ARP learning can be implemented by a modification to the ARP requests processing of the standby node, with a filter list containing a set of match rules for target network addresses. The implementation, thus, can be a configurable filter that enables software modules to specify a set of internet protocol (IP) addresses that the ARP input engine should monitor.

Claims

1. A method, comprising:

receiving an address resolution request from a neighbor node of an active node;

updating an address resolution cache based on information in the request when the request meets a predetermined condition; and

assuming responsibilities of the active node when the active node fails.

2. The method of claim 1, wherein the receiving the address resolution request comprises receiving a broadcast address resolution request.

3. The method of claim 1, wherein the receiving the address resolution request comprises receiving an address resolution protocol formatted request.

4. The method of claim 1, wherein the receiving the address resolution request comprises receiving the address resolution request directly from the neighbor node.

5. The method of claim 1, wherein the updating the cache comprises filtering the request.

6. The method of claim 5, wherein the filtering the request comprises comparing the request to a filter list containing a set of match rules for at least one target network address.

7. The method of claim 1, wherein the updating the cache comprises comparing information in the request to information in the cache.

8. The method of claim 7, wherein the comparing the information in the request comprises identifying whether the information in the request is already in the cache.

9. The method of claim 1, wherein the updating the cache comprises copying previously unknown information from the request into the cache.

10. The method of claim 9, wherein the copying the previously unknown information into the cache comprises creating an entry in a table of the cache.

11. The method of claim 9, wherein the copying the previously unknown information into the cache comprises creating a mapping in the cache.

12. The method of claim 11, wherein the creating a mapping the cache comprises associating a network address with a link address.

13. The method of claim 1, wherein the assuming the responsibilities of the active node comprises detecting the failure of the active node and becoming a newly active node.

14. The method of claim 1, further comprising:

configuring the predetermined condition to be at least one of the request is directed to the active node or the request is from a previously unknown neighbor node of the active node.

15. A network element, comprising:

reception means for receiving an address resolution request from a neighbor node of an active node;

update means for updating storage means for storing address resolution information based on information in the request when the request meets a predetermined condition, wherein the predetermined condition comprises at least one of the request is directed to the active node or the request is from a previously unknown neighbor node of the active node; and

processor means for assuming responsibilities of the active node when the active node fails.

16. The network element of claim 16, wherein the reception means is configured to receive a broadcast address resolution request.

17. The network element of claim 16, wherein the reception means is configured to receive an address resolution protocol formatted request.

18. The network element of claim 16, wherein the reception means is configured to receive the address resolution request directly from the neighbor node.

19. The network element of claim 16, wherein the update means comprises filtering means for filtering the request.

20. The network element of claim 19, wherein the filtering means comprises first comparison means for comparing the request to a filter list containing a set of match rules for at least one target network address.

21. The network element of claim 16, wherein the update means comprises second comparison means for comparing information in the request to information in the storage means.

22. The network element of claim 21, wherein the second comparison means comprises identification means for identifying whether the information in the request is already in the storage means.

23. The network element of claim 16, wherein the update means comprises copy means for copying previously unknown information from the request into the storage means.

24. The network element of claim 23, wherein the copy means comprises creation means for creating an entry in a table of the storage means.

25. The network element of claim 23, wherein the copy means comprises creation means for creating a mapping in the cache.

26. The network element of claim 25, wherein the creation means is configured to associate a network address with a link address.

27. The network element of claim 16, wherein the processor means is configured to assume the responsibilities of the active node by detecting the failure of the active node and becoming a newly active node.

28. A network element, comprising:

a processor; and

a cache,

wherein the processor is configured to receive an address resolution request from a neighbor node of an active node,

wherein the processor is configured to update the cache based on information in the request when the request meets a predetermined condition;

wherein the predetermined condition comprises at least one of the request is directed to the active node or the request is from a previously unknown neighbor node of the active node, and

wherein the processor is configured to assume responsibilities of the active node when the active node fails.

29. The network element of claim 28, wherein the processor is configured to receive a broadcast address resolution request.

30. The network element of claim 28, wherein the processor is configured to receive an address resolution protocol formatted request.

31. The network element of claim 28, wherein the processor is configured to receive the address resolution request directly from the neighbor node.

32. The network element of claim 28, wherein the processor comprises a filter configured to filter the request.

33. The network element of claim 32, wherein the filter is configured to compare the request to a filter list containing a set of match rules for at least one target network address.

34. The network element of claim 28, wherein the processor is configured to compare information in the request to information in the cache.

35. The network element of claim 34, wherein the processor is configured to compare the information in the request by identifying whether the information in the request is already in the cache.

36. The network element of claim 28, wherein the processor is configured to copy previously unknown information from the request into the cache.

37. The network element of claim 36, wherein the processor is configured to copy the previously unknown information into the cache by creating an entry in a table of the cache.

38. The network element of claim 36, wherein the processor is configured to copy the previously unknown information into the cache by creating a mapping in the cache.

39. The network element of claim 38, wherein the mapping is configured to associate a network address with a link address.

40. The network element of claim 28, wherein the processor is configured to assume the responsibilities of the active node by detecting the failure of the active node and becoming a newly active node.

41. A system, comprising:

an active node;

a plurality of neighbor nodes to the active node; and

a standby node configured to update an address resolution cache based on address resolution requests sent by a neighbor node of the active node, when the address resolution requests meet a predetermined condition.

42. A computer program embodied on a computer readable medium, encoding instructions that are configured to cause a hardware device to perform a method, comprising:

receiving an address resolution request from a neighbor node of an active node;

updating an address resolution cache based on information in the request when the request meets a predetermined condition; and

assuming responsibilities of the active node when the active node fails.