6.14.5. Configuring Redundant Ring Protocol

As of Red Hat Enterprise Linux 6.4, the Red Hat High Availability Add-On supports the configuration of redundant ring protocol. When using redundant ring protocol, there are a variety of considerations you must take into account, as described in Section 8.6, “Configuring Redundant Ring Protocol”.

To specify a second network interface to use for redundant ring protocol, you add an alternate name for the node using the --addalt option of the ccs command:

ccs -h host --addalt node_name alt_name

For example, the following command configures the alternate name clusternet-node1-eth2 for the cluster node clusternet-node1-eth1:

# ccs -h clusternet-node1-eth1 --addalt clusternet-node1-eth1 clusternet-node1-eth2

Optionally, you can manually specify a multicast address, a port, and a TTL for the second ring. If you specify a multicast for the second ring, either the alternate multicast address or the alternate port must be different from the multicast address for the first ring. If you specify an alternate port, the port numbers of the first ring and the second ring must differ by at least two, since the system itself uses port and port-1 to perform operations. If you do not specify an alternate multicast address, the system will automatically use a different multicast address for the second ring.

To specify an alternate multicast address, port, or TTL for the second ring, you use the --setaltmulticast option of the ccs command:

ccs -h host --setaltmulticast [alt_multicast_address] [alt_multicast_options].

For example, the following command sets an alternate multicast address of 239.192.99.88, a port of 888, and a TTL of 3 for the cluster defined in the cluster.conf file on node clusternet-node1-eth1:

ccs -h clusternet-node1-eth1 --setaltmulticast 239.192.99.88 port=888 ttl=3

To remove an alternate multicast address, specify the --setaltmulticast option of the ccs command but do not specify a multicast address. Note that executing this command resets all other properties that you can set with the --setaltmulticast option to their default values, as described in Section 6.1.5, “Commands that Overwrite Previous Settings”.

When you have finished configuring all of the components of your cluster, you will need to sync the cluster configuration file to all of the nodes, as described in Section 6.15, “Propagating the Configuration File to the Cluster Nodes”.