what is the 3cx ip address used for?

[Shawn]

i'm not sure if i understand what the purpose of the ip address is on the 3cx side. i have static ip's from two different providers to our building (for redundancy and failover). my firewall is configured with one provider as the primary and fails over to the second provider when primary goes down.

yesterday, this happened and calls where going through but i was having issues with either side not being able to hear each other after the call connected. i am using flowroute with one sip trunk using account base authentication.

i changed the 3cx ip address to the secondary provider static ip and things seemed to start working but i did not have enough time to troubleshoot before primary came back up and we switched back to primary.

what is the proper way to handle the 3cx ip with a setup like mine where we can have 2 ip's but only one in use at any given time?


thanks

 

[Saqqara]

You need to configure your router, to allow traffic in and out using both your IP's as per info
https://www.3cx.com/support/firewall-configuration/

On your router setup the default outgoing route for 3CX traffic to use your primary link,

Configure some sort of detection on router to check each link is up , able to ping flowroute servers, etc. If the primary goes offline, you need to failover to the secondary link, and back to primary when it is back online.

Within 3CX, change your external IP address to 'dynamic public ip' - Settings - Network Settings. This way any remote phones sbc / stun , 3CX apps (windows / mobile) can reconnect using the fqdn address

 

[Shawn]

Thank you for your reply. I'm still not clear on what the Public IP under Network Settings is used for though. My mobile client uses the FQDN under the External PBX IP under the settings of it's configuration.

Incidentally, when I had changed to IP to our backup provider's static IP and have not changed it back but we are now running on the primary provider. I have not noticed any change in behavior. Is this only used for licensing perhaps?

Maybe someone can fill me in on the details of what the Public IP is used for.

 

[Alphabetic]

If you're using a 3CX FQDN, then the FQDN, License and Public IP are bound together. In previous builds of 3CX it was not possible to change the WAN IP without backup/restoring 3CX. Now youre able to change it and restart the services. though, DNS make take some time to update.

 

[Shawn]

I am not using a 3CX FQDN. I have our own company FQDN and manage our own certificate also.
Does this setup still tie the license, FQDN and WAN IP together?
Is the WAN IP used for anything else other than license binding?

 

[pact]

Hi Shawn,

The public IP can also be present in the SIP registration header, so if your Voice Carriage provider still works after the internet failover then this component is ok too.

The 3CX Licence is interested in your hosts MAC address, not the public IP.

If you fully manage your own FQDN (ie not a 3cx.us etc) and you update your public IP in your DNS A Records if the IP changes and your 3CX system is behind the NAT in your router, then I suspect that the answer to your question is 'it does nothing else'.

In previous builds of 3CX it was not possible to change the WAN IP without backup/restoring 3CX. Now youre able to change it and restart the services. though, DNS make take some time to update.

3CX have always allowed IP changes, but until version 15 Dynamic DNS wasn't officially supported, prior to this you had to restart services once you manually put the new public IP in. You were unable to change the FQDN without backup/restore.

 

[YiannisH_3CX]

The public IP is used for registration, for SIP invites for 200 OK messages etc so it is quite useful. If it is set ti static then it will use the static IP specified. If you have the wrong public IP then the provider might be trying to reach you, or send audio to the wrong IP which will obviously cause signalling or audio issues
If Dynamic the PBX will make a STUN request to figure its IP before any action.

 

[Shawn]

So, if I have multiple static IP's from various providers, what does 3CX recommend on how to manage redundancy with these multiple IP's? These IP's get routed to my firewall by the providers and I have no control over that. Once the traffic is at the firewall then I can route and NAT accordingly. Other than changing the WAN IP in 3CX and restarting services, is there an automated method to go about this?
Or, should I / can I assign a private IP in the WAN IP field and NAT accordingly?

Any advice is greatly appreciated on how to handle redundancy at the local level

Thanks

 

[YiannisH_3CX]

If you set the IP of the PBX to Dynamic the PBX will detect the public IP automatically. You might also want to reduce the STUN request query interval under the network settings of the PBX. If you rely on remote extensions you will need update your DNS resolution of the FQDN every time the IP changes.