Server 2003/ISP DNS problem

Ok, I'll try to make this as brief as possible. I have set up server standard ed. 2003 with 2 nics, and 2 routers. The set up that I have is modem -> linksys router #1 (set up with a static ip from my ISP) -> server 2003 (set up as a DC, VPN, DHCP, and DNS server) with a DNS of 127.0.0.1. I have NIC #2 (DNS of 127.0.0.1 as well) -> linksys router #2 set up as DHCP (plugged into the WAN slot) -> LAN using a wireless connection (about 20 pc's). I do have a RJ45 cable connecting the 2 routers mainly for 2 users who are not on the domain just so they can access the internet. We use a lot of .net, sql, oracle, etc. The network was working fine without any problems until unexpectedly, late in the afternoon, when everyone lost connection to the server and the internet. I noticed that the DNS on all of the systems where changed to the ISP's DNS with the exception of 2 laptops. From this point, no one was able to connect to the SQL database. After a couple of minutes most everyone was able to regain access to the internet, except the 2 laptops that were still displaying the local server's DNS. I tried to repair the NIC's on the server. NIC #1 repaired fine except it was still pulling the ISP's DNS, but NIC #2 returned with an ARPcache error. I've tried resetting the routers, and even rebooting the server. When I rebooted the server, the pc's were able to hit SQL, but the server is only utilizing NIC #1, and NIC #2 still isn't able to repair b/c of that ARPcache error. I've been told that it sounds like a hardware failure, but I beg to differ. When it comes to hardware, either it works or it doesn't, and honestly this sounds more like a configuration issue. Really I have 2 questions, why would all of the pc's DNS change to the ISP's instead of the local server's? Also how can/should I go about repairing NIC #2? I've even tried setting the DNS on both NICs to 192.168.1.1 and that really didn't help/hurt the situation. I've already lost countless hours of sleep because of this. I've made sure that NAT has been turned off on both routers, and routher #2 is mainly just working as a switch for the local pc's. Any help or advice would greatly be appreciated.

We have som eissues with this configuration.

1. It is not recommended to run a DC on a multihomed computer.
Name Resolution
Error: target principal name is incorrect · Solved: Master browser
issues · Name resolution resolution and Connectivity Issues on W2K DC with
RRAS and DNS ...
www.chicagotech.net/nameresolution.htm

2. We should not use 127.0.0.1 as DNS and we should setup an internal
DNS.
Troubleshooting DNS
To correct DNS settings and troubleshoot DNS problems, you can
1) run nslookup from a command line is the default dns server the one you
expect. ...
www.chicagotech.net/dnstroubleshooting.htm


3. Also make sure you don't have two default gateways.


--
Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on
http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on
http://www.HowToNetworking.com
"Bryan Godman" wrote in message news:(E-Mail Removed)...
> Ok, I'll try to make this as brief as possible. I have set up server
> standard ed. 2003 with 2 nics, and 2 routers. The set up that I have is
> modem -> linksys router #1 (set up with a static ip from my ISP) -> server
> 2003 (set up as a DC, VPN, DHCP, and DNS server) with a DNS of 127.0.0.1.
> I have NIC #2 (DNS of 127.0.0.1 as well) -> linksys router #2 set up as
> DHCP (plugged into the WAN slot) -> LAN using a wireless connection (about
> 20 pc's). I do have a RJ45 cable connecting the 2 routers mainly for 2
> users who are not on the domain just so they can access the internet. We
> use a lot of .net, sql, oracle, etc. The network was working fine without
> any problems until unexpectedly, late in the afternoon, when everyone lost
> connection to the server and the internet. I noticed that the DNS on all
> of the systems where changed to the ISP's DNS with the exception of 2
> laptops. From this point, no one was able to connect to the SQL database.
> After a couple of minutes most everyone was able to regain access to the
> internet, except the 2 laptops that were still displaying the local
> server's DNS. I tried to repair the NIC's on the server. NIC #1 repaired
> fine except it was still pulling the ISP's DNS, but NIC #2 returned with
> an ARPcache error. I've tried resetting the routers, and even rebooting
> the server. When I rebooted the server, the pc's were able to hit SQL,
> but the server is only utilizing NIC #1, and NIC #2 still isn't able to
> repair b/c of that ARPcache error. I've been told that it sounds like a
> hardware failure, but I beg to differ. When it comes to hardware, either
> it works or it doesn't, and honestly this sounds more like a configuration
> issue. Really I have 2 questions, why would all of the pc's DNS change to
> the ISP's instead of the local server's? Also how can/should I go about
> repairing NIC #2? I've even tried setting the DNS on both NICs to
> 192.168.1.1 and that really didn't help/hurt the situation. I've already
> lost countless hours of sleep because of this. I've made sure that NAT
> has been turned off on both routers, and routher #2 is mainly just working
> as a switch for the local pc's. Any help or advice would greatly be
> appreciated.