Symptom
This issue was seen in case that following device tracking policy was applied to trunk interface.
device-tracking policy /name/
trusted-port
device-role switch
no protocol udp
In case that device will send unicast ARP request towards HSRP VIP address present on Cat9k and this ARP request is received on trunk port with this policy, it will be dropped, e.q. ARP will not be resolved.
Broadcast ARP requests are not affected by this and they will be sucesfully resolved.
Also, unicast ARP request towards physical interface address will be sucesfull. This affects only VIP addresses.
Conditions
- unicast ARP request towards HSRP VIP
- trunk interface with DT policy attached
Workaround
- remove DT policy from trunk interface
