IBM SG24-5131-00 manual Cluster Networks, 1 TCP/IP Networks, Supported TCP/IP Network Types

2.2 Cluster Networks

HACMP differentiates between two major types of networks: TCP/IP networks and non-TCP/IP networks. HACMP utilizes both of them for exchanging heartbeats. HACMP uses these heartbeats to diagnose failures in the cluster. Non-TCP/IP networks are used to distinguish an actual hardware failure from the failure of the TCP/IP software. If there were only TCP/IP networks being used, and the TCP/IP software failed, causing heartbeats to stop, HACMP could falsely diagnose a node failure when the node was really still functioning. Since a non-TCP/IP network would continue working in this event, the correct diagnosis could be made by HACMP. In general, all networks are also used for verification, synchronization, communication and triggering events between nodes. Of course, TCP/IP networks are used for communication with client machines as well.

At the time of publication, the HACMP/ES Version 4.3 product does not use non-TCP/IP networks for node-to-node communications in triggering, synchronizing, and executing event reactions. This can be an issue if you are configuring a cluster with only one TCP/IP network. This limitation of HACMP/ES is planned to be removed in a future release. You would be advised to check on the status of this issue if you are planning a new installation, and to plan your cluster networks accordingly.

2.2.1 TCP/IP Networks

The following sections describe supported TCP/IP network types and network considerations.

2.2.1.1 Supported TCP/IP Network Types

Basically every adapter that is capable of running the TCP/IP protocol is a supported HACMP network type. There are some special considerations for certain types of adapters however. The following gives a brief overview on the supported adapters and their special considerations.

Below is a list of TCP/IP network types as you will find them at the configuration time of an adapter for HACMP. You will find the non-TCP/IP network types in 2.2.2.1, “Supported Non-TCP/IP Network Types” on page 14.

•Generic IP

•ATM

•Ethernet

•FCS

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