Firewall/NAT

Howdy folks.

Well I am new to the m0n0wall world... just "inherited" one that was previously all setup and working smoothly with our Old External IP Address.
We just moved ISP's and have a new external IP...  our Win 2003 Server is running DNS and Web and Exchange on it.
When our external IP changed due to a new ISP... our existing M0n0wall PC's video card died and had to be replaced...
when it was replaced the tech who did it reset it back to factory settings... losing all its configuration.

I am left with the job of getting everything back up and working again ASAP... because the company NEEDs their emails.

First things first... I tried opening all the ports needed for DNS (53 TCP/UDP) but I am still unable to get domain to resolve.
I modified the Registrar entries to reflect the new IP address.. and it is resolving the IP... but it's like its not getting through to the DNS server behind the M0n0wall.

Is there something else I need to do to get a DNS server to work behind a M0n0wall besides NAT/Firewall port 53 UDP/TCP?

I will tackle the mail server ports once I can get DNS to work.

Thank you for your time! I appreciate any and all input...

I would suggest you use your local Windows DNS for internal lookups only and use a service like "no-ip plus" for external DNS.  It's a much cleaner way to configure things and you also end up with a secondary/backup DNS server. Also, this will insure that your external DNS is always  available even when your local DNS is down or your Internet connection is down.

Roy...    

There are two ways this is easily achieved.

1) use windows as primary dns via dhcp , and tell it to use m0n0wall as it's upstream dns server
2) use m0n0wall as primary dns via dhcp, and tell it to use windows for any queries for your windows domain (last option on dns forwarder page)

you can set multiple forwarders in m0n0wall then, and enable 'all servers' option to make sure you use the fastest one.  you can use your isp's forwarders, or specify them, like freedns , or google public dns http://code.google.com/speed/public-dns/