Someone crashed a whole network with a single switch

Solution 1:

I agree with a few of the answers: It could have been caused by STP. Depending on the STP configuration on your switch (if it was configured for STP) and their switches, it could have caused their switches to see your switch as the STP root bridge or as a designated bridge, disrupting the normal packet flow as implemented and designed by your client. It may very well have also introduced a switch loop in to their network. It also could have disrupted traffic, depending on which version of STP is in use, by causing an STP topology recalculation when you plugged in your switch.

Solution 2:

Sounds like Spanning Tree perhaps - but if you literally just uplinked a switch using a single port, that isn't supposed to happen.

Solution 3:

The only way it could be you or your co workers is:

• your laptops have static ips
• your accidently created a switching loop (In which case if its a large network they should have STP setup)
• one of your machines has a DHCP server installed.

Otherwise I cannot see how you caused an entire network to fail. If they have the security you say they do this wouldnt not have happend by plugging in a switch. I think you can sleep easily.

Solution 4:

If the switch you plugged into the network was managed, and also happened to have same static IP address assigned to it as a backbone switch. Sounds like could have added problems mentioned already. Can you attach link of switch or model you brought in?