To operate successfully, the graceful restart function must be supported and
enabled on all peer routers with which the VIPRION®
system exchanges routing information. If one or more peer routers does not support graceful
restart for one or more enabled dynamic routing protocols, a change in the primary blade causes
full dynamic routing reconvergence, and probably traffic disruption. The traffic disruption is
caused primarily by peer routers discarding routes advertised by the VIPRION system.
The BIG-IP system always preserves complete forwarding information (TMM and
host route tables) on VIPRION systems during primary blade changes, regardless of support for
graceful restart on peer routers.