Window Server internal domain vs external website
iis redirect internal domain to external
Same internal/external domain name, used IIS redirect to ...
Forward internal domain to external hosting... ...
split-brian dns system

Our internal domain name is called "abc.com" and our company website is called "abc.com". I have created an "A" record that points to www.abc.com so staff can browse the website from within the office. The problem is that if people enter "abc.com" from a web browser with the office it does not resolve in an efficient manner. Can someone please help?

:

1- put any public dns server as a primary and your internal dns as a secondary on the clients computers and it will work fine.

I rebooted the DNS server/client services on both domain controller and user PC's. then ran the following commands on server/client machines and it kind of worked but it took some time to update. ipconfig /flushdns
ipconfig /registerdns
nbtstat -RR

nbtstat -rr
nbtstat -r
arp -d
the problem I had is different. my website opens inside my domain but recent changes done by web developers take a really long time to load up. the above command helped me with this issue but I would not recommend it though
2-
This scenario is called a Split Zone, where the name is the same internally and externally.
As Jorge indicated, it requires a registry change, but it has to be done on all DCs. This is because it is altering the "same as parent" name in DNS. This record, which many refer to it as the 'blank domain entry' (where you don't need the 'www' in front of it), however, in AD, it's referred to as the LdapIpAddress. This record is used for DFS and GPOs. It's the record your client machines query for when the GetGpoList function runs to retrieve GPOs, among other things.
You can get away with not altering the registry, but it would require installing IIS on each DC. Then in IIS, you can configure a redirect under the Default Website to point to www.abc.com. This is a quick way to handle it, but I don't condone or recommend IIS on a DC.
The third option is to have your users simply live with using www, instead of altering anything on the DCs.
I have more on it in my blog, which you can read at the link below.

Split Zone or no Split Zone - Can't Access Internal Website with External Name
http://msmvps.com/blogs/acefekay/arc...rnal-name.aspx
I hope both my blog and Jorge's blog provides a greater understanding of what's going on in a same internal and external name domain name scenario.