Uplink Failure Detection (UFD) | 235Disabling Uplink Failure DetectionIn some network topologies, you may prefer that downstream links on an Aggregator remain opera-tionally up and continue transmitting traffic without being automatically disabled when connectivity toan upstream switch/router goes down.When UFD is enabled and the upstream connectivity on LAG 128 fails, downstream links are also dis-abled. To avoid this behavior, you can disable the UFD link tracking provided by uplink-state group 1,which associates the upstream connectivity of LAG 128 with downstream connectivity on Aggregatorports.To disable UFD link-tracking, enter the no enable command in uplink-state-group-1 configurationmode.To re-enable the UFD link-tracking configuration, enter the enable command in uplink-state-group-1configuration mode, save the running configuration to startup-config, and reload the switch.Configuring the Defer TimerYou can configure UFD link tracking to use a defer timer before disabling downstream links whenLAG 128, which provides connectivity to upstream devices, goes down.Use the defer-timer command in uplink-state-group-1 configuration mode to configure a timer that pre-vents unwanted flapping of downstream ports when the uplink port channel goes down and comes up.You must save the new UFD setting in the startup configuration and reload the switch to activate thetimer.Task Command Command ModeEnter the uplink-state-group configuration level. uplink-state group 1 CONFIGURATIONDisable the UFD link-tracking configuration. no enable UPLINK-STATE-GROUPTask Command Command ModeEnter the uplink-state-group configuration level. uplink-state group 1 CONFIGURATIONSpecify the time (in seconds) to wait for the upstreamport channel (LAG 128) to come back up before serverports are brought down. Range: 1-120. There is nodefault timer.defer-timer seconds UPLINK-STATE-GROUP
