STUN servers are not reachable. Cannot perform Firewall check. This configuration is not supported

[aslam]

Hi,

I was trying to configure remote extension using STUN but when I do a firewall check in phone system I am getting similar message below

"STUN servers are not reachable. Cannot perform Firewall check. This configuration is not supported"

Our 3CX phone system behind a SonicWall Firewall and I can see the NAT is configured configured correctly ports are forwarded to PBX system . The online resources did not help me to identify and fix the issue. Please help me

 

[complex1]

Hi,

Please disable in 3CX PBX the Windows firewall and run the Firewall Check again.

 

[aslam]

It is already disabled

 

[aslam]

Could you please tell me which stun server I suppose to use and is the anything I need to set up in STUN server. Currently I am using my PBX system as STUN

 

[complex1]

If your PBX is using a static IP address, then there is no need to enabled STUN.
If you are using a dynamic IP address, then you must enable STUN in the PBX.
It is allowed to use the PBX as STUN server for the external phones. At least, I do.

 

[aslam]

Okay, we are using Dynamic IP. One thing which I noticed that outbound NAT policy is not configured in SonicWall. Do you think is it related?

 

[complex1]

I assume you have read and “Create NAT Policies for 3CX inbound and outbound connections” as describe in the How to Configure a SonicWall Firewall?
http://www.3cx.com/blog/voip-howto/soni ... iguration/

I don’t know if a not configured outbound NAT policy is related to your issue because I do not use a SonicWall router.

 

[aslam]

All settings fine except outbound connection. When I try to configure, I could not see an option to "Disable Source Part Remap". Do you have any idea what its for?

 

[complex1]

After doing some search on the internet I found this Release Notes
https://documents.software.dell.com/son ... roduct=849

Are you running the required Firmware version: SonicOS 5.8.1.15o HotFix 152075 ????
https://support.software.dell.com/kb/sw9314

 

[aslam]

Router is configured with 2nd option, ie Many to one NAT Except the setting "Disable Source Part Remap". This option is not available in policy settings.

My router is running with SonicOS Enhanced 5.8.1.8-37o. Does it required any up gradation?

 

[complex1]

My router is running with SonicOS Enhanced 5.8.1.8-37o. Does it required any up gradation?

If Firmware version “SonicOS 5.8.1.15o HotFix 152075” is newer then “SonicOS 5.8.1.8-37o” then Yes, I think so.
You can always check at the Dell site if this is the latest firmware version?

 

[CentrexJ]

Router is configured with 2nd option, ie Many to one NAT Except the setting "Disable Source Part Remap". This option is not available in policy settings.

My router is running with SonicOS Enhanced 5.8.1.8-37o. Does it required any up gradation?

If disable source port remap is missing then your router firmware don't have the hot fix. Contact SonicWall for better firmware.