LAN/WAN configuration with 2 NICs

Hi all,

We are running a Dell server, with 2 nics installed. Recently we got a new ADSL connection, for which we want to use the nic which was unused before that time.

Here's the setup.

NIC1: LAN (connected to 3com switch)
IP: 192.168.0.20
SUBNET: 255.255.255.0
GATEWAY: [empty]
DNS: 192.168.0.20

NIC2: WAN (connected to Allied Data ADSL modem)
IP: 172.19.3.2
SUBNET: 255.255.0.0
GATEWAY: 172.19.3.1
DNS: 192.168.0.20

Until now, I can't seem to get this setup working. Obviously, the main target is te get online, both the server and the rest of the network attached to the switch. The only way I got something working, was when I disabled NIC1 (lan) and entered the DNS of my ISP into the NIC2 tcp/ip properties.

My operating system used is Win2k SBS. My first thought it was a DNS problem, so I started messing in the DNS configuration.
Win2k SBS has a 'internet configuration wizzard' which i've rund dozens of times, but still no luck.

By the given data, does anyone have a clue where things go wrong, or has hints where to look specifically?
Constant IT SupportAsked:
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mikeleebrlaConnect With a Mentor Commented:
this is a basic setup

internet
   |
ADSL "modem"
   |
DSL router (most come w/ a built in switch)
   |
Insert your LAN here (in this case your existing swtich)


now all of your LAN nodes server and clients will/should have a Private IP (you dont want them to have a public IP, not even the server)

the Router will NAT/PAT your one public IP to your nodes so they will all be able to get out to the internet using just the one public IP from your ADSL ISP.  If you want people from the outside to access your server you will need to Port Forward the Port to the private IP that you give to your server.  This port forwarding is done one the router.
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jaguarpriestCommented:
Are you trying to make this some sort of router? if so you need to setup RRAS. Remote access service and set it up as a MultiHomed Routing server. Otherwise it will not work. If that's not the objective. Why do you need 2 NIC's again?

Jaguar
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mikeleebrlaCommented:
jaguarpriest is correct, it sounds like you are trying to use the server as a router and this "can" be done with RRAS (routing and remote access) but i wouldn't recommend it for 2 reasons. The main one is that it is a pain in the butt to set up and the second is that you are then using a server to act like a router.  Why not just go get  a cheap DSL/cable modem router.  Trust me, it will make your life MUCH easier.  Correct me if im wrong, but is the new ADSL connection your only WAN connection?
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Constant IT SupportAuthor Commented:
2 nic's in my opinion are needed because my internet LAN needs one (to get connected with the switch), and the other is needed to connect to my ADSL modem/router.

Believe this is quite a common setup for a server.
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Zaheer IqbalTechnical Assurance & ImplementationCommented:
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mikeleebrlaCommented:
Dennis,,, it is true that it "can" work that way but it is HIGHLY undesirable,,, the main reason is then the internet will be directly connected to your server, with no router/firewall between it,  which you do NOT want at all.
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Constant IT SupportAuthor Commented:
yes, the ADSL connection is our only WAN connection.

The internet setup wizzard does mention an solution where you can choose that the first nic serves the internal network, and the 2nd nic serves the wan part.

Mikeleebria: and this (cheap)modem router would plug directly into the switch?
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Constant IT SupportAuthor Commented:
the ADSL modem has an internal firewall, isn't that exacltly the same as getting an extra dsl router/firewall ?

If I'd plug that extra dsl router/firewall directly into the switch, not only would the SERVER be connected to the Internet but my entire LAN would be. Isn't that even more insecure?
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jaguarpriestConnect With a Mentor Commented:
If you buy a 49 (or Less) lynksys router, the instructions will let you know how to set it up. It's very easy. Your router will have an IP. this will be the Gateway for all your computers and the server. connect all to ONE switch. Actually you need a crossover cable if going from the router to the switch. HOWEVER, most of these routers come with auto sensing uplink ports. Should be fine.

RRAS does work, however you don't want to expose your production server directly to the NET. our .02 cents. It's based on the experience of the proffesionals here.

Glad to help either way you go.

jaguar
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mikeleebrlaCommented:
Jaguar and I seem to both agree that the setup we have mentioned is more secure than the one you are attempting to set up.  Trust us we know what we are talking about. You do NOT want anyone directly connecting to your server and if you give it a public IP that is exacly what you are doing. You need to be doing NAT and PAT.
Thanks,

Mike
CCNA MCSE
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Constant IT SupportAuthor Commented:
Thanks all. Points split.
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