I'm attempting to install a 2nd NIC in my Redhat 5.1 box so that I can connect my wife's laptop and get IP masquerading working. So far, I've had no luck getting the 2 cards to cohabitate. The first NIC (3Com "Boomerang" 900 PCI) has been working fine for months (connected to a cable modem). After installing and configuring the 2nd card (Intel EtherExpress PRO/100) Both NICs initialized just fine, and appeared to be working correctly. I still hadn't managed to get the laptop routed through to the 'net, but I could ping the laptop from the server and vice versa. After a couple of hours and a few reboots, I started having some sort of conflict (xserver could not initialize, and anything requiring a change in video modes would fail). I checked /proc/interrupts, and saw that the 3Com card (cable modem) had been assigned IRQ 11, and the Intel card had been assigned IRQ 9. A buddy of mine told me that IRQ 9 was quirky and shouldn't be used for a NIC. Sounds strange to me, but I disabled IRQ 9 in the BIOS. After re-installing the card and booting linux, BOTH NICs were assigned IRQ 11 (and X video was once again broken...). Is there any way to FORCE a specific IRQ to a PCI card? IRQ 10 is free, no idea why IRQ 11 would be assigned twice. Again, the only real indication that I have that something is wrong is the video card conflict. I have a Diamond Stealth 64 video PCI card, if that's important. BTW -- I used the lilo "append" comand mentioned in the Multiple ethernet card mini-howto to get the 2nd card to initialize. Other than "eth1" I had no idea what the append command was supposed to do. Can I force an IRQ there?
