Problem resolving STUN

[ashwingorityala]

Namaskaram,

I’m hosting 3CX on Windows Server, below is the network at my office

Internet Service: Fiber Optic (from ISP) to ONT (Internet from ISP set to Bridge Mode) LAN1 to WAN1 Fortigate 80F (PPPoE-Dynamic Public IP on Firewall) to Server (xx.xx.53.40)
VoIP Service: Fiber Optic (from ISP) to ONT (VoIP from ISP-DHCP server) LAN2 to WAN2 Fortigate 80F (IP=xx.xx.11.11)

There are few Static Routing rules on firewall to Route VoIP traffic to WAN2

I have two VoIP Services VoIP1 through the ISP and VoIP2 from 3rd Party service

The problem is

1. If I set DNS1: xx.xx.11.1 (Which is ONU LAN2 gateway’s IP) and DNS2: 8.8.8.8
   • Result: VoIP1 registration is successful, VoIP2 registration error unable to resolve DNS, STUN error unable to resolve DNS.
   • Both the VoIP services successful registration on MicroSIP software
2. If I set DNS1: 8.8.8.8 and DNS2: 1.1.1.1
   • Result: VoIP1 registration error unable to resolve DNS, VoIP2 registration successful, STUN no error.
   • Both the VoIP services successful registration on MicroSIP software

Please help me configure my 3CX where both the VoIP services work.

 

[SteveITS]

You can test DNS on Windows by giving nslookup a server:

Nslookup hostname serverIP