BoF - Side Room (Mon, 18:00)

Internet exchanges have presented as shared layer 2 networks for thirty years. I will show the mechanisms that silently blackhole exchange traffic or forward it to the wrong port: missing or incorrect neighbour entries, and unknown unicast flooding. In each case BGP stays established to the route servers and nothing reports a fault.

A large exchange stated in writing that it gives no guarantee traffic sent to a peering LAN goes to, and only to, the port of the network it was meant for, and that…