Linux IPv6 in IPv4 Tunnel (Tunnelbroker)

setup_tunnelbroker.bash

#!/bin/bash
INTERFACE="hev6_tunnel"
SERVERv4_ADDRESS="216.218.226.238"
CLIENTv4_ADDRESS="198.51.100.69"

# Server Tunnel Address for route; Do not enter a prefix here
SERVERv6_TUNADDRESS="2001:470:6969::1"
# Client Tunnel Address; you must have to define a prefix
CLIENTv6_TUNADDRESS="2001:470:6969::2/64"

# Additional v6 Address
ROUTED_FOR_INTERFACE="eth1"
# you must have to define a prefix
ROUTED_IPv6=""

# You need additional settings for firewall
# example: allow IP Protocol 41 (IPv6 Encapsulation) Traffic
#          allow traffic from tunnel interface/server ip traffic.
#          *All firewall rules for IPv6 should be in place.

ip link set $INTERFACE down
ip tunnel del $INTERFACE
ip route del ::/0 dev $INTERFACE

if [ "$1" = "down" ]; then
  echo "The interface $INTERFACE is just down."
  exit
fi

modprobe ipv6
ip tunnel add $INTERFACE mode sit remote $SERVERv4_ADDRESS local $CLIENTv4_ADDRESS ttl 255
ip link set $INTERFACE up
ip -6 address add $CLIENTv6_TUNADDRESS dev $INTERFACE
ip -6 route add ::/0 via $SERVERv6_TUNADDRESS dev $INTERFACE

if [ ! -z "$ROUTED_IPv6" ]; then
  ip -6 address add $ROUTED_IPv6 dev $ROUTED_FOR_INTERFACE
fi