I have a group of phones that are failing to register on the server. In the asterisk logs or realtime asterisk, I see absolutely nothing. However, when I turn on TCP dump, I see the registration request hit the server and a 401 Unauthorized being returned but nothing with the asterisk log.
16:35:43.488317 IP 100.64.17.102.60240 > .sip: SIP: SUBSCRIBE sip:[email protected];transport=UDP SIP/2.0
16:35:43.488520 IP .sip > 100.64.17.102.60240: SIP: SIP/2.0 401 Unauthorized
I have checked all extension secrets etc (multiple times) and everything checks out. There are about a dozen phones doing this from one location [100.64.17.102 is their external address]. About 250 other phones are working just fine.