Hey all, I have been working on getting a my linux router set up. I am using Slackware 12 and everything seems to be working. My problem is only on 1 computer. I have iptables set up CORRECT and the router box is forwarding internet to my laptop - all is well on that connection... But when I connect the lan cable into my other desktop running windows xp ...It still says network cable unplugged. I am not sure if my card has a problem (I am sure that the card IS NOT broke because it works with my linksys router) but it does not auto detect that it is plugged into my linux router. When I plug the cable into my laptop I see the network icon in the bottom right showing it is looking for a connection... But when I plug the same cable into my other box..it does nothing. I have no idea what to do..I know my router works and my laptop works with it, it is my desktop that is having a problem I have even tried a different pci network card...maybe some one can help me diagnose the problem.

I have also messed with the settings in the network card changing the duplex and speed settings..to no avail.

How is your network configured? Are you using a switch in between the laptop, desktop and your linux router? Your problem could be do to several things. If you are connecting the desktop directly into the linux router then you probably need a crossover ethernet cable. GigE network adapters and some 100baseT adapters can auto detect and switch to crossover but your desktop might not have this feature. Another reason is that one of the network adapters can not or is not configured to auto negotiate a connection.

Thanks for the reply. I am not using a switch. I was using a linksys router for my network...but I wanted something with more control so I setup this linux box.
I am connecting directly to my linux box with both the desktop (that doesnt get a connection) and my laptop ( which seems to do the auto detect and switch to crossover ). I am not sure if my network card on my desktop has the auto detect crossover mode feature. Here is the specs of the network card:

NVIDIA nForce Networking Controller
Realtek RTL8201CL PHY- Integrated 10/100 transceiver

This is some of the features of the card ( might be able to do the auto detect thing here...but not exactly sure)

Checksum Offload
Flow Control
IEE802. 1P Support
Jumbo Frame Payload Size
Low Power State Link Speed
Network Addressss
Optimize For
Segmentation Offload
Speed/duplex settings
VLAN Id
VLAN Support
Wake on Magic packet
wWake on pattern
WakeOnLAN From Power Off

Motherboard specs
Viper MSNV-939 ATX Socket 939


* CPU Support: Supports AMD Athlon 64 FX/Athlon 64 X2/Athlon 64/Sempron Processor, socket 939
* Bus Speed: HT 2GHz AMD® Athlon™64 With HyperTransport Technology up to 2G
* Expansion Slots: 4 x PCI, 2 x PCI-E 1x, 1 x PCI-E x 16
* Max Memory: 4 x DDR SDRAM DIMMs
* Chipset: NVIDIA nForce4 (NF4-A9 A)
* Additional Features: ATX Form factor, 16x PCI-E, Onboard 6 Channel 3D Audio, 10/100 LAN 4-USB2.0 + 6 Add ports (10 total USB), 4-SATA 2 RAID 0, RAID 1

I am not sure if I can get this thing to work the way my laptop does. Maybe you have some more ideas of what to change in the card 'features'.

I do not believe the RTL8201CL has auto crossover capability. You will need to build or purchase a crossover cable or assuming your router has more then one LAN port turn off its DHCP function and use it as a switch.

Heh, beat you to it . I just set up my linksys router to forward the internet from my linux router - was going to come here and post a solution - ... and it works!! Thanks for the direction! Got it working perfect.