Full Cone Errors - Firewall Test on Google Cloud

[Bob Denny]

Though our phones are working fine on our PBX Express / Google Cloud, the firewall test shows many Full Cone errors. I can't tell how to mitigate these from Why the Firewall Checker Does Not Lie page under Port Forwarding. The second image below shows the firewall settings.

 

[Alphabetic]

Do you have to specify a source IP or have you been restrictive with your firewall? I've never played with Google's Cloud.

 

[cobaltit]

Bob the errors are likely due to the source restrictions you have on the firewall rules. As everything is working I wouldn't worry about it, but if you want the green check mark you'll need to remove the source filter rules (or disable), run the firewall checker, and then re-enable them.

 

[Bob Denny]

Ok, thanks for that. I will live with it. Without those source rules I would get loads and loads of auto-blacklisted IPs. Somehow the SIP bandits find our PBX. Since we only use soft phones via mobile data (Verizon) and at a few customer sites, I can keep a tight lid on access, and also control the CPU usage responding to trash attempts to register bootleg extensions, etc. If the soft phone fails to register, I run WhatIsMyIp, then create a new allow block on the Google firewall. As you can see in the blurred out image, there aren’t very many. Mostly for certain areas of Verizon mobile data, and I open them as /16 (.0.0) blocks.