System Administration Guide: Network Interfaces and Network Virtualization

Detecting Physical Interface Repairs

When an underlying interface fails and probe-based failure detection is used, the in.mpathd daemon continues to use the interface's test address to continue probing target systems. During an interface repair, the restoration proceeds depending on the original configuration of the failed interface:

To see a graphical presentation of how IPMP behaves during interface failure and repair, see How IPMP Works.

The FAILBACK=no Mode

By default, active interfaces that have failed and then repaired automatically return to become active interfaces in the group. This behavior is controlled by the setting of the FAILBACK parameter in the daemon's configuration file. However, even the insignificant disruption that occurs as data addresses are remapped to repaired interfaces might not be acceptable to some administrators. The administrators might prefer to allow an activated standby interface to continue as an active interface. IPMP allows administrators to override the default behavior to prevent an interface to automatically become active upon repair. These interfaces must be configured in the FAILBACK=no mode. For related procedures, see How to Configure the Behavior of the IPMP Daemon.

When an active interface in FAILBACK=no mode fails and is subsequently repaired, the IPMP daemon restores the IPMP configuration as follows:

Note –

The FAILBACK=NO mode is set for the whole IPMP group. It is not a per-interface tunable parameter.