OpenBSD tunnel keeps losing connectivity

[mattschwartz01]

Greetings fellow IPv6ers! I am having a bit of a problem with my OpenBSD 6.5 gif0 tunnel. The tunnel keeps going down and I have to ping to bring it back up. It shows up in an ifconfig command. I even manually set the mtu to 1480 to match HE's settings. Any idea what could be happening?

[broquea]

Behind NAT/firewall? Sounds like conntrack issues. Tune them or set up an IPv6 keepalive, like NTP queries.