A DoS on the IPs server would do it though, slow down everyones service but I agree, my initial thought is the router is failing but not the NIC because all the computers are experiencing the same issue, not just one.
Here at work I use layer 3 switches that isolate bad packets. But at home I use the same Linksys router everyone else does.
I have 7 machines on the home LAN. My son had a failing NIC (on board, naturally!) and it flooded the LAN with bad packets, no one could do anything. Put a little PCI NIC on his box and it cleared right up.
Oh, learn something new every day. Thanks!
I had a card go bad years ago but it only affected the one computer, didn't realize it could do that.