Comcast6.net PMTU broken
jeroen at unfix.org
Wed Apr 18 00:04:15 CEST 2012
On 2012-04-17 23:24 , Ryan Rawdon wrote:
> From a host behind a 6in4 tunnel a request to www.comcast6.net hangs. It looks like a PMTU brokenness issue since the connection is established and the request is sent successfully.
> Requesting the same page from a host with a 1500B path MTU succeeds.
> nova-dhcp-host111:tmp ryan$ wget http://www.comcast6.net
Try 'tracepath6' it will show you which hop is not returning a packet
too big for that path if needed. Also one can use a series of "ping6 -s
<size> -M do" to check if packets pass or not (if the destination allows
pings of course).
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