PREFIX=$(printf "2002:%02x%02x:%02x%02x" $(echo MYIP_EXTERNAL | tr "." " ") )

/etc/network/interfaces:


[[!format txt """
        up   ip tunnel add tun6to4 mode sit ttl 64 remote any local MYIP_LOCAL
        up   ip link set dev tun6to4 up
        up   ip -6 addr add $PREFIX::1/16 dev tun6to4
        up   ip -6 route add 2000::/3 via ::192.88.99.1 dev tun6to4 metric 1
        up   ip -6 route add $PREFIX:0107::/64 dev local
        down ip -6 route del $PREFIX:0107::/64 dev local
        down ip -6 route flush dev tun6to4
        down ip link set dev tun6to4 down
        down ip tunnel del tun6to4
"""]]


 [[!tag CategoryCodeSnippets]]