Hello,
I noticed that default MTU for tunnel is 1480, this value is ok if connection with Internet has MTU = 1500. In my country Internet providers like to use L2TP or PPPoE to provide internet connection. Because of that default MTU for internet connection is reduced (for example to to 1460 in L2TP case). And because of that my tunnel connection didn't work until I changed tunnel MTU settings.
I propose to change default MTU to 1280 (minimal possible MTU size in ipv6) or move MTU setting on `IPv6 Tunnel` tab and instruct users how to find their MTU.
You are free to set it to the size of your choice.
However, HE should let us have another setting: Simply set it to the jumbo packet size of 9,000 (HE's maximum) and let PMTU size it....