Problem with fail-over

[rvoosterhout]

Hello,

I'm trying to set up a failover situation, when one of our internet connections stop working. We are using an enterprise licence. I already set up the Primary 3cx server, with an company.3cx.nl FQDN. But when I go to backup/restore and I select failover I get the following message:

To configure Failover you need to install 3CX Phone System in Split DNS mode.
Reinstall 3CX Phone System and in the installation mode dialog select this option
Single FQDN - Might require Split DNS or dedicated Domain

But in the setup, I already chose for an 3cx FQDN, which is now connected to my enterprise license.

Am i missing something here?

Kind regards

 

[jed]

SPLIT DNS is for the internel DNS, where you create a Entry for the same company.3cx.nl, but you use the 3CX Server´s internel (local) IP address.
https://www.3cx.com/docs/creating-fqdn-split-dns/

Hope this make sense..

 

[rvoosterhout]

SPLIT DNS is for the internel DNS, where you create a Entry for the same company.3cx.nl, but you use the 3CX Server´s internel (local) IP address.
https://www.3cx.com/docs/creating-fqdn-split-dns/

Hope this make sense..

Hi Jed, thanks for your reply. We do have an internal DNS server (who doesn't..), so by making an entry for company.3cx.nl to my internal pbx IP adres will solve my problem? Or do I still have to reinstall the system?

 

[jed]

@rvoosterhout
It will solve your problem, but I believe that you have to reinstall to select that you use internal DNS.

/Jesper

 

[rvoosterhout]

@rvoosterhout
It will solve your problem, but I believe that you have to reinstall to select that you use internal DNS.

/Jesper

Alright, but I though to be able to use the failover mode, you have to use the 3cx provided FQDN?

 

[jed]

Yes you are going to use the 3CX Provided FQDN that point to the external IP, and you will by creating the same FQDN on your local DNS pointing to the internal IP.. In this way the FQDN is the same, and can be used for Failover.
With your enterprise version you have 2 min TTL (They can change the IP within 2 MIN) When creating the failover you update your internal FQDN (with a script) from pointing to eg. 192.168.1.10 to 192.168.1.11 and in this way your clients will connect to the Failover Server..

 

[rvoosterhout]

Yes you are going to use the 3CX Provided FQDN that point to the external IP, and you will by creating the same FQDN on your local DNS pointing to the internal IP.. In this way the FQDN is the same, and can be used for Failover.
With your enterprise version you have 2 min TTL (They can change the IP within 2 MIN) When creating the failover you update your internal FQDN (with a script) from pointing to eg. 192.168.1.10 to 192.168.1.11 and in this way your clients will connect to the Failover Server..

Hi Jed, thanks for your quick reply!

I start to understand it now. But what if one of the servers won't be in the local network? Then my internal DNS will resole to a server which is not available anymore?
Let write it down:

3cx-primary:
- Installed with 3cx FQDN (company.3cx.nl)
- Uses internal Ip 192.168.0.7
- Writes a backup to google drive every night at 1:00

3cx-secundary:
- Installed with 3cx FQDN (also company.3cx.nl), but when i fill in our licence key, it automatically
connects to the premade FQDN)
- Not inside main office. Uses a different location where we have a already set up internet connection
- Recovers the backup from google drive every night at 3:00

 

[jed]

Hi rvoosterhout

For the DNS to work, then instead of changing the Internal DNS to another internal IP then you must change to the extarnal IP on your Second Location.. This should work, and for SoftPhones without problems, HOWEVER you might have some issues with hardware Phones, as they now will now become "remote phones" to your running 3CX.

If I should reccomend the Enterprise Failover, then I would place both servers internel or both servers external. We are hosting 3CX v15.x and our costumers will always be "remote" extensions nomatter which IP or Server they are using in our hostingcenter. In this way they only need to rely on the Public FQDN, and as it will change automaticly by 3CX we dont have any issues.

If you had both servers inside the same LAN, then your Phones would always be "Internel Extensions" nomatter which server they was using.

Does that make sense ?
Perhaps another in this forum with expirence with same setup as yours might be able to supply with knowledge in this matter..

/Jesper

 

[rvoosterhout]

Hi Jed,

It starts to become somewhat clear. Let me write down the situation i'm trying to create.

We have 2 servers (we use intel NUC), both with a unique IP addres.
3CX-PRIMARY: 1.1.1.1, in office building, with own static IP address.
3CX-SECUNDARY: 2.2.2.2, out of office, also with own static IP address.

In the 3CX console, I have all the phones provisioned to the external 3CX FQDN. In our in office DNS server, i have no record stating office.3cx.nl. This is because i want to force the phones to look at the 3CX FQDN, not an internal IP address.

- When the primary server fails, the secundary doesn't receive an hearbeat anymore.
- The secundary will change the IP adres from the 3CX FQDN (that's why we needed an Enterprise licence), to the Static WAN IP of the secundary.
- All the phones will still be looking at company.3cx.nl, but this address now refers to the external IP of the secundary server. So the phones will be able to call again.

I believe this is the situation described at https://www.3cx.com/docs/failover/, which i'm trying to implement here.

I hope my explanation is clear, please send me a direct message if you have any more questions regarding our system.

Rick