Technical Considerations for a Serviceguard Cluster that Spans Multiple IP Subnets, July 2009

5
Note:
Cross-subnet support does not include automatic notification of a change to
the application servers’ IP address to the application clients.
Figure 1 shows a non-cross-subnet cluster with two dedicated heartbeat networks. Each heartbeat
network (5.1.1.0 and 5.1.2.0) is a single subnet that exists on all cluster nodes.
Figure 1 – A non cross-subnet cluster where the subnets are the same on all the nodes
Figure 2 shows a cross-subnet cluster with two dedicated heartbeat networks. Each heartbeat network
spans two subnets which are routed to each other. The first heartbeat network consists of subnet
5.1.1.0 on node A and node B and subnet 5.2.1.0 on node C and node D. Similarly, the second
heartbeat network consists of subnet 5.1.2.0 and subnet 5.2.2.0.
Figure 2 – A cross-subnet cluster where the nodes are on different subnets