Configuration support for backup liveness detection between multichassis link aggregation peers

Backup liveness detection determines the peer status (that is, whether the peer is up or down) by exchanging keepalive messages between two MC-LAG peers on a configured IP address. MC-LAG peers use an Inter-Chassis Control Protocol (ICCP) connection to communicate. When an ICCP connection is operationally down, a peer can send liveness detection requests to determine the peer status. If a peer fails to respond to the liveness detection request within a specified time interval, the liveness detection check fails and the peer is concluded to be down. To configure backup liveness detection between MC-LAG peers, use the backup-liveness-detection backup-peer-ip backup-peer-ip-address statement at the [edit protocols iccp peer] hierarchy level.