DNS Records – Understanding Serial Number in DNS Records

Some people will say no public DNS records should ever disclose private IP addresses....with the thinking being that you are giving potential attackers a leg up on some information that might be required to exploit private systems.

Personally, I think that obfuscation is a poor form of security, especially when we are talking about IP addresses because in general they are easy to guess anyway, so I don't see this as a realistic security compromise.

The bigger consideration here is making sure your public users don't pickup this DNS record as part of the normal public services of your hosted application. ie: External DNS lookups somehow start resolving to an address they can't get to.

Aside from that, I see no fundamental reason why putting private address A records into the public space is a problem....especially when you have no alternate DNS server to host them on.

If you do decide to put this record into the public DNS space, you might consider creating a separate zone on the same server to hold all the "private" records. This will make it clearer that they are intended to be private....however for just one A record, I probably wouldn't bother.

A CNAME Record must be the only record for a DNS Record. Most common gotcha is that you can not create a CNAME for mysite.com since you also have a NS Record and most likely a MX record for that name.

As long as you have singular occurrences of names I would recommend using CNAME since it makes you more flexible. When you migrate to another server you would just have to take care of changing the name that all CNAMEs point to.