We have a W2K standard server used as web server that can access
external
sites / hosts by IP address, but not by hostname.

nslookup shows that DNS is working fine and it can resolve hostnames
to ip fine. But, when trying to use IE, or ASP mail directed to a
hosted mail server on the same network (mail.domain.com) it will fail
and gives an "Unknown host mail.domain.com" error.

Using any browser by hostname fails with server can't be found. Use
http:// ip address and it works fine.

Incoming traffic works fine, but there are some sites on the server
are using ColdFusion's cfhttp to
access remote data, as well as posting credit card data through custom
tags to processors using hostnames and not ip addresses.

Everything in the network control panel seems fine, and again using
nslookup from the cmd prompt indicates that DNS resolution is working
fine.

I know you said nslookup shows DNS is fine but, can you you ping a host name
successfully (like google.com)?

Did you check Settings in IE to make sure it isn't pointing to a Proxy
server, under the Connections/LAN Settings tab?



"Steve" <steve.logan@gmail.com> wrote in message
news:fdf8c57b-9fc7-41ae-bb8e-33203ae5e0d0@f63g2000hsf.googlegroups.com...
> We have a W2K standard server used as web server that can access
> external
> sites / hosts by IP address, but not by hostname.
>
> nslookup shows that DNS is working fine and it can resolve hostnames
> to ip fine. But, when trying to use IE, or ASP mail directed to a
> hosted mail server on the same network (mail.domain.com) it will fail
> and gives an "Unknown host mail.domain.com" error.
>
> Using any browser by hostname fails with server can't be found. Use
> http:// ip address and it works fine.
>
> Incoming traffic works fine, but there are some sites on the server
> are using ColdFusion's cfhttp to
> access remote data, as well as posting credit card data through custom
> tags to processors using hostnames and not ip addresses.
>
> Everything in the network control panel seems fine, and again using
> nslookup from the cmd prompt indicates that DNS resolution is working
> fine.
>