Cluster Slave rejecting login due to multiple ip's

Hi all,
After recently losing my beloved Webmin\Virtualmin server thanks to a host losing everything, I decided to setup a slave that would act as a slave dns and backup mail server.

Everything seemed to be going ok but then i noticed that the slave was rejecting some of the updates from the main server.

Having a look through the logs I realised that the master has 2 ip’s and that when it updated from one ip it was accepted but rejected from the other.

I followed the instructions here and did the “Setting the Master IP Address” but only for one. Then i added a space and added the second ip, but that still didnt work either?

I also noticed that when i run a check Virtualmin configuration on the master server I get the following error,

“Default IP address is set to, but the detected external address is actually This is typically the result of being behind a NAT firewall, and should be corrected on the module configuration page.”

Could that be the cause of the issue? Errors on Slave log:

backup named[527]: client received notify for zone ‘
backup named[527]: zone refused notify from non-master:


backup named[527]: client query (cache) ‘’ denied