Thank you so much for this thread! I've had my he.net tunnel up and running with no obvious issues for years, but was recently trying to get a remote Plex media server to stream video over IPv6. IPv4 was fine but it buffered constantly over IPv6. I assumed it was my ISP (Virgin Media in the UK) applying traffic shaping to the 6in4 traffic but seeing this thread made me check the MTU on the 6in4 interface. It defaults to 1280! Changing it to 1480 (I'm on a cable modem in modem mode) results in great quality streaming over IPv6
(I'm so annoyed with myself for not thinking to check this before )
Hummm...I have a slightly different config...no ifname whatsoever.
config interface 'henet'
option proto '6in4'
option peeraddr '216.xxx.xxx.xxx'
option ip6addr '2001:4xxx:xxxx:xxxx:xxxx:2/64'
option ip6prefix '2001:xxxx:xxxx::/48'
option mtu '1480'
# I use DDNS for the following now - but they did work for me
option tunnelid 'xxxxxxxx'
option username 'xxxxxxxx'
option password 'xxxxxxxx'
You can also get come config hints from the Example Configurations screen on the Tunnebroker website - that's how I configured my first OpenWrt for IPv6:
[Slightly OT] I recently (late January 2019) updated the 6in4 Hurricane Electric tunnel docs at Setting up an IPv6 Tunnel with LuCI, partly to get out of the business of editing config files.
I haven't done a diff against your configs and my instructions, but if you find any errors in my instructions, I'd be delighted to fix them.
Update: That page also has links to tunnelbroker.sh script that automatically reconfigures a HE.net tunnel - I found it useful when I was re-flashing my router on a weekly basis while testing firmware.