Failure detection is the process of detecting when an interface or the path from an interface to an Internet layer device no longer works. IPMP provides systems with the ability to detect when an interface has failed. IPMP detects the following types of communication failures:
The transmit or receive path of the interface has failed.
The attachment of the interface to the IP link is down.
The port on the switch does not transmit or receive packets.
The physical interface in an IPMP group is not present at system boot.
After detecting a failure, IPMP begins failover. Failover is the automatic process of switching the network access from a failed interface to a functioning physical interface in the same group. Network access includes IPv4 unicast, multicast, and broadcast traffic, as well as IPv6 unicast and multicast traffic. Failover can only occur when you have configured more than one interface in the IPMP group. The failover process ensures uninterrupted access to the network.