Bidirectional Forwarding Detection (BFD) protection of Border Gateway Protocol (BGP) peering sessions allows for the rapid detection of link failures such that peering sessions can be taken out of the "established" state within fractions of a second. This allows the protocol to select an alternate path (if available) to a destination immediately after the link failure, rather than waiting until the BGP hold timer expires (180 seconds by default).
This feature applies to both IPv4 and IPv6 peering sessions. Both IPv6 global and link local peering sessions are supported.