Address family independence (1)

Host name resolution - DNS or /etc/hosts

"www.kame.net" can return both IPv4 and IPv6 addresses

"telnet turmeric.itojun.org" should try both IPv4 and IPv6
"telnet4" then "telnet6" is a pain
transition has to be transparent (invisible) to users

So, need address family independent APIs behind-the-scene

$ORIGIN itojun.org.
turmeric        IN      HINFO   "VAIO 505EX" "NetBSD"
                IN      AAAA    2001:218:420:0:2e0:98ff:fe00:309f
                IN      AAAA    3ffe:501:410:0:2e0:98ff:fe00:309f
                IN      A       210.160.95.98