The udpport directive specifies which port Heartbeat[1] will use for its UDP[2] intra-cluster communication. There are two common reasons for overriding this value: there are multiple bcast[3] clusters on the same subnet, or this port is already in use in accordance with some locally-established policy.
The default value for this parameter is the the port ha-cluster in /etc/services (if present), or 694 if port ha-cluster is not in /etc/services. 694 is the IANA registered port number for Heartbeat (a.k.a. ha-cluster).
A sample udpport directive is shown below.
udpport 694
NOTE: The GUI doesn't use UDP, and isn't intracluster communications, so GUI communication is not affected by this directive.
BUGS: Due to a specification error in the syntax of the mcast[4] directive, this directive does not apply to mcast communications.
| [1] | http://www.linux-ha.org/HeartbeatProgram |
| [2] | http://en.wikipedia.org/wiki/User_Datagram_Protocol |
| [3] | http://www.linux-ha.org/ha.cf/BcastDirective |
| [4] | http://www.linux-ha.org/ha.cf/McastDirective |
This information provided courtesy of the Linux-HA project at http://linux-ha.org/