On 21/05/2015 03:49, Nico Williams wrote: > On Tue, May 19, 2015 at 09:17:37PM -0600, Doug Royer wrote: >> On 05/19/2015 06:49 PM, Christopher Morrow wrote: >>> sure, v6 works. if you see connect but hang I'd suspect pmtu >>> problems (at first guess). >> >> Don't understand why yet. By moving the MTU from 1500 (the default >> value) to 1420, it works. > > Make sure ICMP isn't getting filtered. Or fragments being dropped. https://tools.ietf.org/html/draft-ietf-v6ops-ipv6-ehs-in-real-world Or MSS negotiation failing. Brian