Windows
Phone system needed a firewall rule updated to include an additional IP
The phone system stopped working even though internet access was still up. The firewall rule was updated to include another IP address, and the customer was asked to test the phone system afterward; the ticket does not record the test result.
Killed once by someone from XL.net, on 2026-01-14.
What you see
- Phone system stops working while internet access still works.
Why it happens
Likely A firewall rule likely did not include the IP address the phone system needed.
When it shows up
A phone system fails and the only change found is in firewall access for one or more IP addresses.
You are in this case if:
- A firewall rule needs an additional IP address added for the phone system.
- No existing rule is found for the other IP address mentioned in the ticket.
1 fix below
The steps that killed it
The steps are behind a quick check
There are two ways in and both take a few seconds. Signing in opens the steps on every bug page; so does reading the picture.
Or answer this
Drawing a picture for you.
Can't read it? Sign in instead.
Someone from XL.net killed this on a Windows computer on 2026-01-14. It is written up from that one repair, so it cites no outside page.