Description of problem: A split brain can occur if the tiebreaker IP address is on one network while the cluster is communicating over another. Version-Release number of selected component (if applicable): All, up to and including 1.2.22 How reproducible: 100% Steps to Reproduce: 1. Configure a 2-node cluster using either multicast or broadcast with "clumembd%primary_only" enabled. 2. Set communication paths (node names) on one network 3. Set tiebreaker IP on another network which is separate from the communication network (one which uses different physical NICs). 4. Start both nodes 5. Wait for quorum 6. Unplug one node's cluster communication link. Actual results: Split brain. Both nodes ping the IP tiebreaker and believe they are the sole member of the cluster, even though the tiebreaker is on the wrong network. Expected results: Unknown; this is a misconfiguration. Cluster Manager requires that all members coexist on the same fully connected subnet and that the link(s) used for cluster communication are the same link(s) used to monitor the tiebreaker IP address. Additional info: We could possibly detect that the IP tiebreaker is on the same network and refuse to use it if it is not, but this would be an undesirable enhancement in some cases where users use something outside their LAN for the tiebreaker IP address (for instance, their ISP's router). * This behavior does not occur in 2-node clusters where the disk tiebreaker is in use. * This behavior does not occur in 2-node clusters utilizing broadcast heartbeat (with clumembd%primary_only disabled) in Cluster Manager versions 1.2.23 and higher.