I just had a weird experience on my home network. Our ethernet went down; pinging an adjacent host was impossible. I checked the switch; all lights were on and flickering, although they were flickering in synch which was a bit worrying. Then I noticed that my Linux box had crashed (unresponsive to mouse and keyboard). I hit the reset button, and at that moment the network cleared.
This would be of only academic interest, except that my employer happens to be in a business where service continuity is of great importance. Critical data is sent over dual independent ethernet LANs. Our reliability models assume that the only thing that could take down an entire LAN is a failed switch. So the idea that a single malfunctioning host could do it is ... worrying.
This message on a Cisco forum says its impossible so don't worry.
This report about an outage in the US Customs sounds similar: a malfunctioning Ethernet card bought down their network. That was a single network and it sounds like a hardware fault, so it wouldn't bring down both of our dual networks. But I'm wondering: could a device driver bug wedge a card into a state where it was jamming the network? If so then if it was driving two bonded channels it might wedge both in the same way.
Does anyone know more about the potential failure modes of Ethernet?
What I'm trying to understand is: what could a single node do in software (e.g. in a device driver) that could bring down the entire network. Lets assume that its not malware, so obscure bugs of specific switches are probably not an issue. Sending frames to a single specific host won't do it. Would sending lots of broadcast frames (destination FF:FF:FF:FF:FF:FF) have this effect? What about jabber? Is that a thing still?