Solved Firewall Checker Fails on most RTP ports

[theMightyMacBoy]

I have setup a 3CX server to use for our company and configured our firewall ports and NATing. When I run the firewall test, the first several ports pass but then the rest fail. I am source and destination NATing all ports on one public IP for 3CX, so I don't understand why the first several ports pass then the rest fail. I am running 3CX on Debian and we are using Sophos UTM for firewall. I cannot figure this out for the live of me. I have moved these NAT rules to the top to eliminate any other rules from applying. Nothing else is using this public IP, so I am lost.

 

[cobaltit]

Have you reached out to Sophos support?

 

[YiannisH_3CX]

Hello @theMightyMacBoy

It could be that your firewall thinks it is being attacked because of all the ports checked and drops the connection. If so then it is just doing it's job. I am not familiar with Sophos firewalls but search for any flood protection settings.

 

[theMightyMacBoy]

That's exactly waht it was @YiannisH_3CX! I had to go into the IPS and make an exception for this. The IPS logs were showing it was being blocked for port scan. I toggled these on and firewall test passed. I am going to toggle these back off, as the firewall / NAT is set right. The IPS should be enabled to protect the PBX and these should only need toggled to verify the check.

Possibly a fix could be for the 3CX management console to have a custom parameter for the test of the ports so they don't flood the IPS system and cause alarm. Just a thought.

Thanks for the pointer.

 

[YiannisH_3CX]

Glad to see the issue has been resolved and thank you for the feedback. I believe that leaving the option on should not give you any troubles as normal usage should not trigger the anti-port scanner module.