ifconfig gif0 inet6 3FFE:1200:3028:FF01::f7b 3FFE:1200:3028:FF01::f7a
prefixlen 128 tunnel 216.30.51.217 64.71.128.26 gives me the following
error:

ifconfig: error in parsing address string: No address associated with
hostname

It looks like the problem is that ifconfig is calling getaddrinfo on the
tunnel source/destination IPv4 addresses with PF_INET6 in the
hints.ai_family (because of the "inet6" earlier). getaddrinfo returns
EAI_NODATA since those IP addresses aren't IPv6.

Any thoughts about what should be done? Maybe just set hints.ai_family
to PF_UNSPEC? That let me get my tunnel configured, at least...
-- 
Name: Dave Huang         |  Mammal, mammal / their names are called /
INet: khym@azeotrope.org |  they raise a paw / the bat, the cat /
FurryMUCK: Dahan         |  dolphin and dog / koala bear and hog -- TMBG
Dahan: Hani G Y+C 25 Y++ L+++ W- C++ T++ A+ E+ S++ V++ F- Q+++ P+ B+ PA+ PL++