On Tue, May 19, 2015 at 11:17 PM, Doug Royer <douglasroyer@xxxxxxxxx> 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. clearly there's a lower mtu (perhaps tunneled?) path between you and the ietf rsync host. traceroute6 ?