Yes, under certain circumstances. Firstly, there is the condition known as jabber where the card's electronics go brain dead and it keeps transmitting all or most of the time, jamming the segment it is on. This is less likely to cripple an entire network these days with our switched infrastructures but it's worh bearing in mind. Another is where the card is partly faulty and so much of what it sends has errors, resulting in loads of retransmissions which soak up the network bandwidth. This might be a genuine fault or a configuration error (e.g duplex mismatch). And while not really a card fault, if there is a misconfiguration a a higher level (e.g duplicate IP address, spanning tree issue, routing anomaly) this can cause a single 'card' to play havoc with your network.
Are you having a specific problem? If so, give us the symptopms and any tests you have undertaken to try to isolate the problem
