Method and system for filtering inter-node communication in a data processing system

• US 20020124105A1
• Filed: 03/05/2001
• Published: 09/05/2002
• Est. Priority Date: 03/05/2001
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Block, Timothy Roy, Sand, Thomas Rembert, Booth, Richard Charles, Engebretsen, David Robert, Valk, Kenneth Micheal
• Granted Patent: US 6,944,155 B2
• Time in Patent Office: Days
• US Class Current: 709/238
• CPC Class Codes: H04L 49/3009 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches

Abstract

A method and system for communication in a system area network (SAN) data processing system are described. The SAN includes a plurality of interconnected nodes that each have at least one port for communication. To avoid communication-induced errors that may arise, for example, if multiple nodes share the same node ID, the port of a node in the SAN is marked as “fenced” to prevent transmission of packets of a first traffic type while permitting transmission of packets of a second traffic type. The marking of the port may be recorded, for example, in a configuration register of the port. While the port is fenced, only packets of other than the first traffic type are routed via the port. In one preferred embodiment, the second traffic type represents SAN configuration traffic, and the first traffic type represents non-configuration traffic. In this preferred embodiment, the marking of the port may be removed following communication of configuration traffic utilized to negotiate unique node ID throughout the SAN.

Claims

1. A method of communication in a system area network including a plurality of interconnected nodes that each have at least one port, said method comprising:

marking a port to prevent transmission to another node of packets of a first traffic type while permitting transmission to another node of packets of a second traffic type; and

thereafter, routing via said port only packets not of said first traffic type.

2. The method of claim 1, and further comprising storing a routing table that associates ports with node identifiers, and wherein routing comprises routing by reference to said routing table.

3. The method of claim 2, wherein marking said port comprises marking said port in a port configuration register.

4. The method of claim 1, and further comprising determining a traffic type by reference to a packet header.

5. The method of claim 1, said first traffic type comprising non-configuration traffic and said second traffic type comprising configuration traffic, wherein marking comprises marking said port to prevent transmission to another node of packets of nonconfiguration traffic while permitting transmission to another node of packets of configuration traffic.

6. The method of claim 5, and further comprising following transmission of packets of configuration traffic, removing said marking of said port.

7. The method of claim 6, and further comprising:

in response to transmission of said packets of configuration traffic, altering at least one node identifier used in packet routing.

8. The method of claim 1, wherein marking comprises automatically marking in response to said port being unconnected at initialization of the system area network.

9. A node for a system area network, said node comprising:

at least one device coupled to a network chip having a port for interconnection to another node, wherein responsive to said port being marked to prevent transmission of a first traffic type via said port while permitting transmission of packets of a second traffic type, said network chip routes via said port only packets not of said first traffic type.

10. The node of claim 9, and further comprising a routing table accessible to said network chip that associates ports with node identifiers, wherein said network chip routes packets by reference to said routing table.

11. The node of claim 10, and further comprising a port configuration register containing said marking of said port.

12. The node of claim 9, wherein said network chip determines a traffic type of a packet by reference to a packet header of the packet.

13. The node of claim 9, wherein said first traffic type comprises non-configuration traffic and said second traffic type comprises configuration traffic.

14. The node of claim 13, wherein following transmission of packets of configuration traffic said network chip removes said marking of said port.

15. The node of claim 14, wherein said network chip, responsive to transmission of said packets of configuration traffic, alters a node identifier used in packet routing.

16. The node of claim 9, wherein said network chip marks said node automatically marking if said port is unconnected at initialization of the system area network.

17. A system area network, comprising:

a plurality of interconnected nodes including at least one node according to claim 9.

19. The network chip of claim 18, and further comprising a routing table that associates said port with node identifier of at least one of said plurality of nodes, wherein said means for routing routes packets by reference to said routing table.

20. The network chip of claim 19, wherein said means for marking comprises means for marking said port by setting a port configuration register.

21. The network of claim 18, wherein said network chip comprises means for determining a traffic type of a packet by reference to a packet header of the packet.

22. The network chip of claim 18, wherein said first traffic type comprises non-configuration traffic and said second traffic type comprises configuration traffic.

23. The network chip of claim 22, and further comprising means for, following transmission of packets of configuration traffic, removing said marking of said port.

24. The network chip of claim 23, and further comprising means, responsive to transmission of said packets of configuration traffic, altering a node identifier used in packet routing.

25. The network chip of claim 18, wherein said means for marking comprises means for automatically marking said port if said port is unconnected at initialization of the system area network.

18. A network chip for a node in a system area network including a plurality of nodes, said network chip comprising:

a port for inter-node communication;

means for marking the port to prevent transmission to another node of packets of a first traffic type while permitting transmission to another node of packets of a second traffic type; and

means for, if said port is marked, routing via said port only packets not of said first traffic type.