lulz:~# ifconfig
eth0      Link encap:Ethernet  HWaddr C2:57:12:87:D7:03
          inet addr:89.46.37.168  Bcast:89.46.37.255  Mask:255.255.255.0
          inet6 addr: fe80::c057:12ff:fe87:d703/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:126095 errors:0 dropped:0 overruns:0 frame:0
          TX packets:42880 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:54832693 (52.2 MiB)  TX bytes:112824084 (107.5 MiB)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:55 errors:0 dropped:0 overruns:0 frame:0
          TX packets:55 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:7409 (7.2 KiB)  TX bytes:7409 (7.2 KiB)

lulz:~# cat > 6to4.sh
export MYHOST=`wget -O /dev/stdout -q -4 http://whatismyip.org`
export HOST=`printf "2002:%02x%02x:%02x%02x::" \`echo ${MYHOST} | tr "." " "\``
export JHOST=`printf "2002:%02x%02x:%02x%02x:" \`echo ${MYHOST} | tr "." " "\``
echo "IPv4 host: ${MYHOST}  IPv6 host: ${HOST}1"
ip tunnel add tun6to4 mode sit ttl 0 remote any local ${MYHOST}
ip link set dev tun6to4 up
ip -6 addr add ${HOST}1 dev tun6to4
echo "Adding IPv6 route"
ip -6 route add 2000::/3 via ::192.88.99.1 dev tun6to4 metric 1
add_ipv6_hosts


lulz:~#
lulz:~# clear
lulz:~# ifconfig
eth0      Link encap:Ethernet  HWaddr C2:57:12:87:D7:03
          inet addr:89.46.37.168  Bcast:89.46.37.255  Mask:255.255.255.0
          inet6 addr: fe80::c057:12ff:fe87:d703/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:128768 errors:0 dropped:0 overruns:0 frame:0
          TX packets:44559 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:55791619 (53.2 MiB)  TX bytes:116960695 (111.5 MiB)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:55 errors:0 dropped:0 overruns:0 frame:0
          TX packets:55 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:7409 (7.2 KiB)  TX bytes:7409 (7.2 KiB)

lulz:~# cat > 6to4.sh
export MYHOST=`wget -O /dev/stdout -q -4 http://whatismyip.org`
export HOST=`printf "2002:%02x%02x:%02x%02x::" \`echo ${MYHOST} | tr "." " "\``
export JHOST=`printf "2002:%02x%02x:%02x%02x:" \`echo ${MYHOST} | tr "." " "\``
echo "IPv4 host: ${MYHOST}  IPv6 host: ${HOST}1"
ip tunnel add tun6to4 mode sit ttl 0 remote any local ${MYHOST}
ip link set dev tun6to4 up
ip -6 addr add ${HOST}1 dev tun6to4
echo "Adding IPv6 route"
ip -6 route add 2000::/3 via ::192.88.99.1 dev tun6to4 metric 1

lulz:~# chmod 755 6to4.sh
lulz:~# ./6to4.sh
IPv4 host: 89.46.37.168  IPv6 host: 2002:592e:25a8::1
Adding IPv6 route
lulz:~# ifconfig
eth0      Link encap:Ethernet  HWaddr C2:57:12:87:D7:03
          inet addr:89.46.37.168  Bcast:89.46.37.255  Mask:255.255.255.0
          inet6 addr: fe80::c057:12ff:fe87:d703/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:129258 errors:0 dropped:0 overruns:0 frame:0
          TX packets:44876 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:55873626 (53.2 MiB)  TX bytes:117650683 (112.2 MiB)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:55 errors:0 dropped:0 overruns:0 frame:0
          TX packets:55 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:7409 (7.2 KiB)  TX bytes:7409 (7.2 KiB)

tun6to4   Link encap:IPv6-in-IPv4
          inet6 addr: 2002:592e:25a8::1/128 Scope:Global
          inet6 addr: ::89.46.37.168/128 Scope:Compat
          UP RUNNING NOARP  MTU:1480  Metric:1
          RX packets:2 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:208 (208.0 b)  TX bytes:248 (248.0 b)

lulz:~# ping6 irc6.oftc.net
PING irc6.oftc.net(2001:610:6b1:0:a8cc:ff:fe10:105) 56 data bytes
64 bytes from 2001:610:6b1:0:a8cc:ff:fe10:105: icmp_seq=1 ttl=59 time=116 ms
64 bytes from 2001:610:6b1:0:a8cc:ff:fe10:105: icmp_seq=2 ttl=59 time=116 ms
64 bytes from 2001:610:6b1:0:a8cc:ff:fe10:105: icmp_seq=3 ttl=59 time=115 ms
64 bytes from 2001:610:6b1:0:a8cc:ff:fe10:105: icmp_seq=4 ttl=59 time=116 ms

--- irc6.oftc.net ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3054ms
rtt min/avg/max/mdev = 115.860/116.161/116.372/0.199 ms