If a system loses connectivity to another, message IXC409D is issued, and the operator can try to re-establish connectivity or remove the system from the sysplex.

Or, if all systems are running OS/390® or MVS/ESA SP Version 5, the sysplex failure management policy can be used to isolate one or more disconnected systems from the sysplex. See Handling signaling connectivity failures.

Note that if a structure used for signaling fails and there is no alternate signaling path, signaling connectivity is lost until the structure is rebuilt. During this time, if the sysplex failure management (SFM) policy is active, SFM might take action before the structure is rebuilt, and the sysplex could end up with only one surviving system. Therefore, signaling path redundancy is strongly recommended, particularly when SFM is active in the sysplex.