This is exactly the issue comcast6.net is currently experiencing :). They seem to be blocking ICMP completely and that is causing my HE IPv6 tunnel to be unable to access their site from a browser.
On Jul 5, 2012, at 1:41 PM, William Herrin wrote: > On Thu, Jul 5, 2012 at 1:20 PM, Darius Jahandarie <[email protected]> > wrote: >> On Thu, Jul 5, 2012 at 1:11 PM, Oliver Garraux <[email protected]> wrote: >>> Seems fairly straightforward to me. It'll break path MTU discovery. >> >> Since Bill said "(not IP in general, TCP specifically)", I don't think >> PMTUD breaking is what he's looking for. > > No, path MTU discovery is the answer I'm fishing for. The stack > notifies TCP of the fragmentation needed message and TCP handles it > within the TCP stack. Managing path MTU discovery is specific to each > layer-4 protocol even if the trigger message (destination unreachable, > fragmentation needed but DF set) is the same. > > If a candidate gives me a more clever answer, I'd take that too. :-) > > "This would block all IP traffic." is not a correct answer. It's not > even a naively incorrect answer. > > Regards, > Bill Herrin > > > -- > William D. Herrin ................ [email protected] [email protected] > 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> > Falls Church, VA 22042-3004 >
