Symptom

When C9300-NM-4M FRU is used in cat9300 switches, during xFSU/reload fast traffic downtime will be less than or equal to normal reloads.

Conditions

Issue is seen when the traffic is flowing through the links from the uplink module (FRU) C9300-NM-4M

Workaround

This is not seen with other type of FRU like - C9300-NM-8X , C9300-NM-2Q . There is no workaround when the C9300-NM-4M FRU is involved, traffic downtime will be less than or equal to regular upgrades (without using xFSU)

Further Problem Description