I have a small question (maybe I'm sutpid) about
	sys/netinet6/ip_icmp.c:icmp_mtudisc().

	The function makes cloned route for recording PMTU for peer,
	and assigns timeout function (icmp_mtudisc_timeout) to the route entry.
	The function calls rtfree() at the end, so it sets reference count
	on route entry unchanged.

	My question is, who makes sure that the entry is still there on
	the call to icmp_mtudisc_timeout(), usually happens 10min later?
	My imagination was that icmp_mtudisc() would increase reference count
	on the route entry for that (by NOT calling rtfree()), but the
	implemented behavior does not match my imagination.  Could someone
	let me know the trick? (or am I lucky?)

itojun