An open invitation to D-Link, NetGear, etc. DISABLE ANYTHING IN YOUR DAMNED ROUTERS THAT MIGHT FILTER ICMP UNREACHABLEs.
We’ve been seeing occasional problems with a tunnel “somewhere” on the internet getting into our path. It shouldn’t be a problem except that it seems a lot of firewalls still filter ICMP Unreachable’s at the least.
DON’T DO THAT.