Split-DNS scenario ok, if an additional external mail domain is used ?

[john99]

Hi,

we intend to install Zimbra in a test environment behind a firewall in a DynDNS domain with NAT.
Do to redundancy reasons, we will receive and send our mails through an ISP (external mail domain)


Is your Split_DNS scenario as well recommended for such an environment?


Thank's a lot you for any feedback!

John

[phoenix]

Split DNS is necessary whenever you are behind a NAT device, it makes delivery of mail to Zimbra (postfix) possible.

[john99]

Thank's a lot phoenix for your feedback!

What would be the advantage of installing an internal DNS server in the described environment?


Thank you in advance for additional help!

John

[phoenix]

The advantage is that your mail gets delivered. As I mentioned above, Postfix requires it so it can deliver the mail to your server, it uses a DNS lookup to resolve your server address.

[john99]

Thank's for the reply!

-> we intend to install Zimbra in a test environment behind a firewall in a
-> DynDNS domain with NAT.


My believe was that a local DNS server could offer some benefits, but that it's not a requirement.
But as I understand you now, a local DNS server is absolutely required...

Is that the case?


Thank you very much!

John

[phoenix]

Yes, that is the case. If you are behind a NAT router or firewall then it is a requirement to have a DNS server. There is a benefit in that you don't have to rely on your ISPs DNS servers for resolution of external addresses.