citation for what? ;-) That PMTUD just works is not my experience, especially with IPv4, there are lots of servers/sites out there that break if you don't mang

citation for what? ;-) That PMTUD just works is not my experience, especially with IPv4, there are lots of servers/sites out there that break if you don't mangle the MSS if you are behind some link with an MTU < 1500--unfortunately. But yeah, let's hope that your article will help spread the word that PMTUD is important, and that completely filtering ICMP is idiotic--in any case it has helped remove an "incompetent" flag for your company in my brain ;-)