CFM enhancement for interoperability during unified ISSU

Junos OS connectivity fault management (CFM) works during a unified in-service software upgrade (ISSU) when the peer device is not a Juniper Networks router. Interoperating with the router of another vendor, the Juniper Networks router retains session information and continues to transmit CCM PDU (continuity check messages) during the unified ISSU upgrade. To provide this interoperability, enable inline (Packet Forwarding Engine) keepalives with the hardware-assisted-keepalives statement at the [edit protocols oam ethernet connectivity-fault-management performance-monitoring] hierarchy level. You must also configure the continuity-check interval to 1 second with the interval statement at the [edit protocols oam ethernet connectivity-fault-management maintenance-domain domain-name maintenance-association ma-name continuity-check] hierarchy level. Interoperability during unified ISSU is not supported for any other interval value.