ARP issues between Nexus 7K and F5 LTM

Hi Thiyagu,

Just to confirm: how many IPs do you use to send GARP?

Our team has currently found an issue similar to yours, during failover, production traffic is not moving correctly to the primary device, through packet capturing we found out that it is the F5 sending huge amount of GARP packets during failover, which triggers the CoPP of the N9K, which drops the excessive GARP packets, resulting in the MAC table not being updated, and all the traffic returns are still being sent towards the standby device.
In 25 minutes time, that's when the MAC table ages before N9K correctly learns the correct new MAC.

A few of our practices include:
Modify the value of CoPP on the N9K, the default value is 1400kbps.
Limit the number of GARPs sent per second by F5, I think articles K11985 and K7332 can help.
Please note that these are just small practices that apply to me, please carefully consider and think about the feasibility of the specific operation.
If you have other things to share you can let me know and we can discuss it together.🙂