Multiple public IPs

[choimarc]

Hello,

We are installing a secondary ISP connection. We have a single instance of 3CX on-premise server. How do I configure 3CX to be able to leverage connections from both ISP (2 different static public ip). My provisioning is done with an external public DNS. I can configure the external DNS, I can configure my firewalls, but what happens on the 3CX server ? I don't want to have an additional 3CX server.

Thanks.

Marco.

 

[leejor]

You will have issues trying to use two public IPs at the same time. You can have two, but only use one at a time, as only one will resolve to your FQDN, and that is what providers and devices are probably set to use when connecting to the PBX. You would have to set up as if you did not have a static IP (use STUN), as it sounds as if it could change at any time.

I'm sure others will have some ideas as as well.

 

[choimarc]

Hello,

I know that I have to use only one at the time. What I don't know is how to configure 3CX to allow both IP to work. It could change at any time because I cannot predict when my main ISP connection will fail. It should be a rare thing.

Thanks.

 

[leejor]

You will probably have to set your public IP as Dynamic, as suggested in the response here...

https://www.3cx.com/community/threads/how-to-change-public-ip.56060/

Just be advised that 3CX recommends using a Static Public IP and if there is a delay in updating DNS records when your IP changes, you will probably have issues. Hopefully changing the IP is not done on a regular basis, and is reserved only for occasions when the first "link" fails.

 

[choimarc]

Do I leave the primary stun server stun-us.3cx.com or do I put my public dns ?

Thanks.

 

[leejor]

When using STUN, you should be able to put in any working (open) STUN server you choose to use. It is simply a standardized tool. They should all behave in the same manner.

https://en.wikipedia.org/wiki/STUN

Your DNS is not a STUN server.