Some icmp6 sample rules

At various points in your network, you may need selections of these:

## allow icmp6 for getting address using IPv6 autoconfiguration from router
pass inet6 proto ipv6-icmp all icmp6-type routeradv
pass inet6 proto ipv6-icmp all icmp6-type routersol

## allow icmp6 for getting neighbor addresses
pass inet6 proto ipv6-icmp all icmp6-type neighbradv
pass inet6 proto ipv6-icmp all icmp6-type neighbrsol

## allow icmp6 echo, not required, but sometimes nice
pass in inet6 proto ipv6-icmp all icmp6-type echoreq

## pass icmp-types: unreachable, time exceeded, parameter problem
pass in inet6 proto ipv6-icmp all icmp6-type {1 3 4}

Thanks to Henrik Kramshøj for input