Why are external NICs not working on my server (running on Debian 7)?

Question

I have a server running Debian 7. The eth0 interface is configured to use the on-board ethernet card. This is basically used to connect to the internet. As it happens, I had to connect this server to some PCs through a switch, obviously on a different series of IPs. for this, I installed an external NIC in the PCI slot but, strangely it didn't seen to work. The configurations were alright. I checked them more times than I can imagine. So, I disabled my eth0 interface and connected eth1 (external NIC) to the internet. If for the same settings, the on-board card worked, so should the external one. But, it didn't. When I tried to ping some servers like 8.8.8.8, it gives me Destination Host Unreachable and on termination shows, 0 packets "transmitted" and 0 packets received, which is baffling, to say the least. The PCI slot is working because I checked if the drivers were being recognised or not. The NIC itself is working (checked with another machine running Debian 6). Any help/sugesstions would be appreciated.

PS The NIC in question is D-Link System DGE-530T Gigabit Ethernet Adapter (rev 11)

Answer 1

You need to check to see if the card is being listed in lspci or not. Second, is this a virtual machine?

I would also check to see if the BIOS is handling IRQ's in auto or are they specifically assigned.