VCS requires you to set up a private network between the systems that form a cluster. You can use either NICs or aggregated interfaces to set up private network.
You can use network switches instead of hubs.
Refer to the Veritas Cluster Server User's Guide to review VCS performance considerations.
Figure: Private network setups: two-node and four-node clusters shows two private networks for use with VCS.
Symantec recommends configuring two independent networks between the cluster nodes with a network switch for each network. You can also connect the two switches at layer 2 for advanced failure protection. Such connections for LLT at layer 2 are called cross-links.
Figure: Private network setup with crossed links shows a private network configuration with crossed links between the network switches.
To set up the private network
Install the required network interface cards (NICs).
Create aggregated interfaces if you want to use these to set up private network.
Use crossover Ethernet cables, switches, or independent hubs for each VCS communication network. Note that the crossover Ethernet cables are supported only on two systems.
During the process of setting up heartbeat connections, consider a case where a failure removes all communications between the systems.
Test the network connections. Temporarily assign network addresses and use telnet or ping to verify communications.
LLT uses its own protocol, and does not use TCP/IP. So, you must ensure that the private network connections are used only for LLT communication and not for TCP/IP traffic. To verify this requirement, unplumb and unconfigure any temporary IP addresses that are configured on the network interfaces.
The installvcs program configures the private network in the cluster during configuration.
More information about configuring LLT for the private network links is in the manual installation chapter.