We have noticed over the past few days that our IP (dynamic) is being blacklisted because of failed SIP registrations. I can't work out why this is happening, but it seems to be a problem with an expired IP still being stored somewhere.
The IP address 92.227.31.* has been blacklisted for 60 minutes because there were 4 unsuccessful authentication attempts (sip).
REGISTER sip:***.eu SIP/2.0
Via: SIP/2.0/UDP 78.51.207.*:64567;branch=z9hG4bKe3t97xvquk3criszb
Max-Forwards: 70
From: <sip:3431@***.eu>;tag=g9w.sbs
To: <sip:3431@***.eu>
Call-ID: 05ve9z3jk.wg.
CSeq: 35604 REGISTER
Contact: <sip:3431@78.51.207.*:64567;line=26375>
Allow: INVITE, CANCEL, BYE, ACK, REGISTER, OPTIONS, REFER, SUBSCRIBE, NOTIFY, MESSAGE, INFO, PRACK
Expires: 600
User-Agent: snom-m3-SIP/02.11 (MAC=0004132A****; HW=1)
Content-Length: 0
The IP 78.51.207.* hadn't been assigned to the phone for about 18 hours. The current IP is 92.227.31.* and this is the one that is being blacklisted. Each time it seems to be adifferent extension.
Is this a phone problem or a PBX problem? I don't want to disable blacklisting, but we can't have our phones deregistering every day because of this. I have tried to find the cause of the problem but nowhere is there any record of the old IP not expiring.
Is there any way to whitelist phones apart from with the IP, which we can't because they are dynamic?