#> ping6 ipv6.google.com
PING ipv6.google.com(ber01s02-in-x6a.1e100.net) 56 data bytes
From 2001:0:d91f:cc9a:20e2:6c5d:b17f:5e80 icmp_seq=11 Destination unreachable: Address unreachable
From 2001:0:d91f:cc9a:20e2:6c5d:b17f:5e80 icmp_seq=12 Destination unreachable: Address unreachable
From 2001:0:d91f:cc9a:20e2:6c5d:b17f:5e80 icmp_seq=13 Destination unreachable: Address unreachable
From 2001:0:d91f:cc9a:20e2:6c5d:b17f:5e80 icmp_seq=14 Destination unreachable: Address unreachable
From 2001:0:d91f:cc9a:20e2:6c5d:b17f:5e80 icmp_seq=15 Destination unreachable: Address unreachable
From 2001:0:d91f:cc9a:20e2:6c5d:b17f:5e80 icmp_seq=16 Destination unreachable: Address unreachable
^C
--- ipv6.google.com ping statistics ---
16 packets transmitted, 0 received, +6 errors, 100% packet loss, time 15013ms


#> ifconfig 
(...)
teredo    Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  
          inet6 addr: 2001:0:d91f:cc9a:20e2:6c5d:b17f:5e80/32 Scope:Global
          inet6 addr: fe80::ffff:ffff:ffff/64 Scope:Link
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1280  Metric:1
          RX packets:146 errors:0 dropped:0 overruns:0 frame:0
          TX packets:272 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500 
          RX bytes:146102 (142.6 Kb)  TX bytes:23516 (22.9 Kb)