I've got a MikroTik router set up with the latest stable OS on it, and I just set up an ipv6 tunnel with Hurricane Electric, but I'm having an odd issue with it. I can't ping anything until I first ping the tunnel endpoint on HE's side. After that I can ping any ipv6 address fine, but give it a little time (say, maybe 30 sec) and I can't ping any ipv6 addresses again. Whenever it stops allowing ping to go through I notice the counter on my firewall rule that drops invalid connections goes up.

this is my ipv6 firewall config:

add action=accept chain=input comment="" connection-state=established \ disabled=no in-interface=sit1 add action=accept chain=input comment="" connection-state=related disabled=no \ in-interface=sit1 add action=accept chain=input comment="" disabled=no in-interface=bridge \ src-address=ipv6_address_here/64 add action=drop chain=input comment="" connection-state=invalid disabled=no \ in-interface=sit1 add action=drop chain=input comment="" disabled=no in-interface=sit1

Any ideas on what it could be?