3CX FQDN TTL

[Samfiller]

Good afternoon to all,

Just posting some information 3cx provided me with, this is the first time I have seen this and thought it may be helpful for others.

Please note that the TTL of the FQDN is related to the license that you have:

1. Pro->6 hrs
2. Enterprise->5 min

Why is this important?
The scenario I see this most an issue is in a WAN failover setup.

Customer has two internet connection (Primary and failover) the provider is sending inbound calls at their FQDN as it “should” be updated when they failover.
They fail-over and the 3cx FQDN takes 6 hours to update…

Anyone else think TTL should be set to 5 min as long as its a paid license?

Thanks!

 

[eryp]

I agree. I've had this cause trouble in two cases:

1. WAN failover with local server and remote clients
2. Re-installing or moving instances in the cloud due for various reasons outside my control

Even setting the TTL down to 1 hour would help quite a bit. I understand that they want to offer the lower TTL for the Enterprise version. Can't blame 3CX there but 6 hours is excessive.

 

[AWS2P]

You need ENT licence to have this short as possible.

We are not in 3CX marketing decision, they do as they do , so you have choice as you were surprised to choose Pro licence or ENT licence with best short time to refresh DNS

 

[cobaltit]

https://www.3cx.com/docs/fqdn-management-allocation/

The TTL information is also listed on that page and is mentioned quite a few times on the forums but it looks like you're new on here.

Anyways, I think it's just fine as it is. If your business requires and you can afford multiple internet connections for redundancy then you can afford to upgrade your license. Or use a provider that is registration-based or one that can send to multiple IPs instead of a single target . You can also use your own FQDN and manage your own TTLs. Or get a SD WAN solution manages the IP so it doesn't change when you failover.

 

[Samfiller]

@cobaltit - Great post!

 

[eryp]

SD-WAN makes it all so much easier.