Domain naming problems

[Spider]

I remember reading before that having an internal (LAN) domain the same as your external web domain is a bad idea and can cause a lot of problems. I didn’t, however, read the explanation of why this is a bad idea and what problems it causes.

Does any know why this is considered a bad practice and what issues it could cause?

 

[csmager]

One or more of your DCs will run a DNS server. All DNS queries will be forwarded to one of your internal DNS server, which will then either do the lookups itself or forward them onto your ISP, depending how you configure it.

Say you had the domain www.domain.com, and you named your internal domain domain.com. You have an external website, but your internal domain server think they're responsible for the domain... so anyone in your company who types www.domain.com will get a response that it doesn't exist or it's an internal website.

You can enter these specifically on the internal DNS servers to point to the right place, but if you have a lot it can be a hassle to keep two copies of the DNS up to date (one internal, one external). Far easier to just call your internal domain something like ad.domain.com instead.