Symptom
In Nexus 9k, global TACACS keys got deleted from the switch after the switch is upgraded from 10.2.4 to 10.3.3 version
Conditions
ISSU upgrade or disuptive upgrade and using type 7 encryption global TACACS key and faced only with PID N9K-C93108TC-FX3P
Workaround
Manually add the tacacs-server key.
# conf t
Enter configuration commands, one per line. End with CNTL/Z.
(config)# tacacs-server key 7 "omitted"
(config)# end
# copy run start
--or--
Use per-server keys which are not impacted by this issue.
Further Problem Description
Similar behaviour was observed in multiple switches which were upgraded from 10.2.4 to 10.3.3
