New Public Static IP - DNS Failing To Update

[Alan9846]

Hi All,

I have a client that has moved to a new static IP, but DNS is not updating. It has now been a few hours since the changeover.

I have changed the IP setting from:

Settings > Network > Public IP > External IP Configuration
I have then changed the setting to: Dynamic Public IP (IP changes)

On the Dashboard, the IP shows correctly (as the new one), but with a red background and with the word 'Dynamic' at the end.


The hostname is of the form:

example.my3cx.nz

If I query, say Google's DNS (8.8.8.8) it shows the old static IP still, but that could be due to the TTL meaning it has not expired yet, so I queried for the authoritative namerserver like this:

nslookup
set querytype=SOA
example.my3cx.nz

I get:

my3cx.nz
primary name server = ns-cloud-d1.googledomains.com
responsible mail addr = cloud-dns-hostmaster.google.com
serial = 1
refresh = 21600 (6 hours)
retry = 3600 (1 hour)
expire = 259200 (3 days)
default TTL = 300 (5 mins)

If I then:

nslookup
server ns-cloud-d1.googledomains.com
example.my3cx.nz

I get:

Server: ns-cloud-d1.googledomains.com
Addresses: 2001:4860:4802:32::6d
216.239.32.109

DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
*** Request to ns-cloud-d1.googledomains.com timed-out



Am I doing something wrong to check what the authoritative nameserver returns?

Should the authoritative nameserver be responding to me?

Is there a problem at 3CX and / or Google (seems unlikely) or have I done something wrong / failed to do something (seems more likely!)


Thanks,

Alan.

 

[cobaltit]

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

When you use a 3CX FQDN, the DNS TTL (time to live) depends on the 3CX License used. Standard and Professional licenses have a TTL of 6 hours. Enterprise Editions however, set the TTL to 300 seconds. This allows for immediate failover which will update the 3CX FQDN to the IP of the new server in less than 5 minutes. The shorter the TTL, the quicker the FQDN Mapping to IP updates.

 

[Alan9846]

Thanks @cobaltit - I didn't know that. I will wait until later.


In terms of what I tried above, do you know what I am doing wrong?

Even if the TTL is six hours, shouldn't I be getting a response from (ns-cloud-d1.googledomains.com) albeit with the old IP address?

Thanks,

Alan.

 

[cobaltit]

Honestly I haven't tried querying directly before but it's possible it's trying IPv6 and timing out. Can try setting the server directly to the IPv4 address.

 

[Alan9846]

Is that different from what I did above?

nslookup
server ns-cloud-d1.googledomains.com
example.my3cx.com

How do I set the server directly to the IPv4 address?

Also, it has now been about seven hours, and DNS still hasn't updated. I still get the old IP on my ISP's DNS server, and also on Google's (8.8.8.8).

Thanks,

Alan.

 

[cobaltit]

Instead of doing server ns-cloud-d1.googledomains.com you can do server 216.239.32.109

 

[cobaltit]

At this point thought I'd restart the server if possible just to make sure it kicked it over. And the license is current and you are on at least v15.5 Update 6 right?

 

[Alan9846]

Hi,

I have rebooted the server, and the license is definitely current, and running the latest version:

Product	Professional Annual
Version Number	16.0.676
License Expires	12/30/2019 10:24:18 PM

I did as you suggested to explicitly connect via IPv4:

nslookup
server 216.239.32.109
example.my3cx.nz

That fixes the timeout issue, but confirms that DNS has not updated, as it reports:

Server: ns-cloud-d1.googledomains.com
Address: 216.239.32.109

Name: example.my3cx.nz
Address: {OldStaticIP}


I am confuddled!

Alan.

 

[AWS2P]

I've been in similar process last weekend, i'm in south east France and we have got severe weather conditions with floods.
There was a general outage of our ISP in our region, after that when service come back we've been with problems on certain PBX from these who use this ISP.

Finally FQDN was not resolving anymore on static public ip used until this outage, so i've just done on PBX these steps. 3CX Licence is a PRO

1. changed network from Static to dynamic, let 3CX like that for a while
2. Then re-set to static with new public one received (completely changed)
3. Dashboard came back to green with new static IP

Then i've done a flushdns on my computer, and almost 5 minutes after FQDN was resolving on new IP and console was available remotely

 

[Alan9846]

Hi aws2p,

Thanks for that - I did exactly those steps, and it has now resolved the situation.

Public DNS is now resolving to the new IP address.

Thanks!

Alan.