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NT server is not IP forwarding

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13 replies

by jp.

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I need to build a NT server box with 2 NICs which will route IP requests from one IP to another (basiclly acting as a router). One NIC for interenal network, one for external.

When I install NT server, enable both NICs with the ip ranges and addonly one with the default gateway, I find that it does not forward the IP on.

What am I doing wrong?

13 replies

by timthetoolman

Hi,

...I should have noticed your second question before I responded to your first...

Ummm... I know this is going to sound obvious but you didn't mention checking the "Enable IP Forwarding" on the routing tab of the nics' IP properties?

Cheers,
Tim.

by bhrdwh

Need to enable "IP Forwarding" on the Routing tab of the Network Neighbourhood - IP properties. Thats all.
Also check if you are having any firewall after the NT Server.

Akash

by gurjots

Also check if the route is correctly configured in the routing table you might need to add a route to the external network. If you have other subnets within your network you may need to install RIP for IP so that the route tables are in Sync. I hopeit is a simple NT box with out Proxy or a firewall!!!

by isys

Each NIC should have a gateway. What you are setting up is a bridge, not a router. Add a gateway to the other NIC and it should work OK.

by jp.

Yep IP forwarding has been enabled, that is why I am confused.

here is a copy of the route table

Network Destination Netmask
Gateway Interface Metric

127.0.0.0 255.0.0.0
127.0.0.1 127.0.0.1 1

192.168.1.0 255.255.255.0
192.168.1.4 192.168.1.4 1

192.168.1.4 255.255.255.255
127.0.0.1 127.0.0.1 1

254.102.143.64 255.255.255.192
254.102.143.70 254.102.143.70 1

254.102.143.70 255.255.255.255
127.0.0.1 127.0.0.1 1

254.102.143.255 255.255.255.255
254.102.143.70 254.102.143.70 1

224.0.0.0 224.0.0.0
192.168.1.4 192.168.1.4 1

224.0.0.0 224.0.0.0
254.102.143.70 254.102.143.70 1

255.255.255.255 255.255.255.255
254.102.143.70 254.102.143.70 1

Sorry about the format but it is the best I can do.

Any Ideas?

by curlergirl

The IP setup appears OK as far as it goes. What does your ipconfig /all show? Why do you say that it is not IP forwarding? Do you have people trying to get in from the outside that cannot? Are you using some sort of VPN setup? Just trying to figure out exactly what you're trying to accomplish. If you're trying to get workstations to be able to get out to the Internet, then you need something besides simply using your server as an IP forwarder - you need to do a NAT translation or use proxy or firewall software so that the workstations can share the single external IP address and have the packets forwarded properly internally. The external packets coming in don't have anywhere to go after they reach the server, because they have already reached their destination - the server's routable IP address. Hope this helps!

by jp.

Thank you for your help.

I found what the problem was and I am embarrassed to say. In my panic with the NT box I forgot to add the route back on the Routers.

Simple, easy, stupid mistake...all my trade marks.
Thanks anyway for all your suggestions.

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