Some of the management plane issues can lead to authorization failures or protocols such as NTP and SNMP going down. Most problems arise due to mismatching community or mismatching IP addresses configured for the peer and the actual address that is being sent by the peer. Hence, it is recommended to use the source interface as loopback interface and peer.
The commands that can be used to validate the source address in the management packets are show run | inc trap-source and show run | inc ntp source.
Further, the ACLs, if any, which are used to control access for SNMP to NOC servers should have the right IP address. This can be seen using the show access lists command.
Debugs can also be used to debug ...