Migrating 3CX to a new subnet

[samkahanda]

Hi,
We run 3cx on NX32 Lite box. recently we restructured our network and tried to migrate the 3CX box and the phones to a new subnet. Everything seems to work except that the external calls via SIP trunk connect but no voice is carried.
1) Old IP 192.168.71.9/24 -> the new IP 192.168.73.9/24
2) All the port forwarding is done on the router. well just need to change the IP of the SNAT to the new IP. everything works fine when the NX32 is in 192.168.71.0/24 subnet.
3) I have taken a tcpdump and can see that the SIP messages are working fine between the trunk provider (BreezeConnect) and the NX32 - well that's why the calls connect - but no voice is heard.
4) Plus, when I ran the firewall test it fails on communicating with the STUN servers and RTP ports. but as I have mentioned the port forwarding rules are in place and works fine with the original subnet.

Is there anything else that I need to do in addition to reconfiguring the NX32 ethernet interface to the new IP? Any config change to be done on the 3CX admin web GUI?

 

[ThomasD_3CX]

Hi,

In regards to the local IP change, on the 3CX System all you have to do is to update the local IP under Settings > Network and restart all 3CX services (upon IP change you also get a warning under 3CX Dashboard)

Now firewall checker test may fail for numerus reasons, network related. This guide explains how 3CX Firewall checker works which will help you identify reason it is failing. This is the first thing that must be checked and fixed.

Under Sip Trunk configuration ensure that under Sip Trunk > Options > "Select which IP to use in 'Contact' (SIP) and 'Connection'(SDP) fields make" that the correct public IP is used.

Under users > Phone Provisioning (tab) ensure that the IP Phones are configured to use the correct interface.

Also I would recommend using a 3CX Webclient to perform the tests, in order to eliminate a potential issue in the local network (possible connectivity issue between an IP Phone and the 3CX System).

 

[samkahanda]

Hi,

In regards to the local IP change, on the 3CX System all you have to do is to update the local IP under Settings > Network and restart all 3CX services (upon IP change you also get a warning under 3CX Dashboard)

Now firewall checker test may fail for numerus reasons, network related. This guide explains how 3CX Firewall checker works which will help you identify reason it is failing. This is the first thing that must be checked and fixed.

Under Sip Trunk configuration ensure that under Sip Trunk > Options > "Select which IP to use in 'Contact' (SIP) and 'Connection'(SDP) fields make" that the correct public IP is used.

Under users > Phone Provisioning (tab) ensure that the IP Phones are configured to use the correct interface.

Also I would recommend using a 3CX Webclient to perform the tests, in order to eliminate a potential issue in the local network (possible connectivity issue between an IP Phone and the 3CX System).

Hi Thomas,
Thanks for the reply. Will check the local IP setting next time I try to migrate. This is the one thing I missed!!
Will check on the firewall as well but as I have mentioned, only thing I change at the time of the migration is to change the SNAT to the new IP.
Phones use the internal URL which is resolved to the correct local IP by the internal DNS. And they work fine even with the remote mobile clients. But I will check with the web client next time.

Thanks again and will let you know how I went the next time.

 

[ThomasD_3CX]

@samkahanda

Thank you for the feedback as well as the additional info you have provided about the issue.

 

[samkahanda]

@ThomasD_3CX I have done the migration successfully. Issue was that the 3CX box was picking the wrong interface as the default internet facing address. Now everything is ok. Thanks for you help.