They're also too stupid to understand that they've been dropping UDP datagrams with src port == dst port and < 1024. This obviously breaks IPsec IKE. I showed them dummy traffic captured with netcat and tcpdump, but they refused to admit they caused the problem. They repeatedly claimed to see nothing dropped between the pcap files, that I was doing it to myself with a firewall that wasn't even enabled, or that this is just how a network is supposed to work.