War Stories

A customer appears to have drastically misunderstood our instructions for connecting to our WAN. He set his PC IP address to the same as one of the bridges. This caused much confusion on the network, to put it mildly. He called to complain about the poor performance of the network he ruined, then made himself unavailable for phone calls so it couldn't be fixed.

Even blocking his MAC address didn't help. The bridging problem happens in midair, nowhere the server can control. If I could at least get into the bridge, I could reconfigure it to a different IP and allow traffic again...

So, on the server, I tried this:

Code:

arp -d 192.168.6.101 ; arp -s 192.168.6.101 00:60:b3:07:0e:8e

This succeeded in forcing the server to talk to the bridge, not to him. I was then able to get into the bridge's web interface and change its IP from there. From there it was easy.