Solved DNS issues with SIP Trunks on Host 3cx System

[Anthony - Sedcom]

Hi

I have a new client we are going to help manage and having some issues

They are moving there SIP lines to my business

I have had zero issues with my lines on any of my 3CX systems

But this one

This System is a 3CX hosted system (we dont use 3CX Hosted systems normally)

I have completed my Sip info like any of my other dozen + systems and no issues

but this one is giving me errors on DNS resolving

Error: Registration at Sedcom has failed. Destination (sip:xxx.xxx.xxx.xxx:5060;lr) is not reachable, DNS error resolving FQDN, or service is not available.

Note I have removed the IP and replaced with xxx for security sorry guys

It feels like 3CX hosted is blocking my SIP Trunk Registration

I have Whitelisted the IP address of my provider and still nothing

Does anyone know how to get past this issue with 3CX hosted Systems

 

[Anthony - Sedcom]

Ok I Have just Spun up a Test Hosted system on 3CX and they are blocking the Domain name of my SIP Provider

 

[TheodorosG_3CX]

As per our ticket conversation the PBX does sent the Registration attempts but the unsupported sip provider does not respond back:


As mentioned there is no issue with the Hosted installation and this has to be checked from the Provider side. Keep in mind that it is suggested that a 3CX Supported Provider is always used to avoid any issues like this.

 

[SteveITS]

is not reachable, DNS error resolving FQDN, or service is not available.

Note this generic message will show for several reasons, such as a firewall block, IDS block on the server end, etc., not just DNS. I also had it for one of several IPs once where someone tried to enter Allow rules but accidentally left the Action at the default Deny value for one.

 

[Anthony - Sedcom]

I hate Generic messages does not help and leads down the wrong paths


Well I have found out my Upstream Carrier blacklisted the 3CX Hosted systems IP address

Have it all working now