Symptom
TRACK operations can go down with just a couple of timeouts in spite the DELAY Down configured on the TRACK.
Conditions
When DELAY Down is configured, the expectation is that TRACK will change Reachability status to DOWN only if all icmp-echo proves sent withing the DELAY Down period of time are not responded.
The fact is, if there is one timeout, the delay down countdown timer will start until the period of time configured has been reached, if all next proves are replied/responded but the prove at the very last moment of the delay down fails/timeout the TRACK will go down in spite all previous proves were replied/responded.
Tested on Nexus 7009 (Nexus 7000 9 slots) versions 8.3(2) and 7.3(2)D1(2)
Further Problem Description
ip sla 1
icmp-echo 8.8.8.8 source-interface Vlan1
frequency 5
ip sla schedule 1 life forever start-time now
track 1 ip sla 1 reachability
delay down 180
Example:
- 1 icmp-echo timeout
- Next icmp-echos are replied/responded.
- 170-175 seconds before there is another timeout, then the TRACK will go down.
- Next icmp-echos are replied/responded, then TRACK will go UP.
