setup linux isatap client

#!/bin/bash

export LC_ALL=C

MYIP=$(ip r g 8.8.8.8|head -n 1|sed 's/.*src \([0-9.]*\) .*/\1/')

PHY6=$(ip -6 a s scope link|head -n 1|sed 's/^[^a-z]*\([a-z]*[a-z0-9]*\).*/\1/')

GATEWAY=172.31.7.26

DEVNAME=ipv6

MTU=1440

echo ipv4=$MYIP dev=$PHY6

ip tunnel delete $DEVNAME

ip tunnel add name $DEVNAME mode isatap remote $GATEWAY local $MYIP ttl 64

ip link set $DEVNAME up

ip tunnel prl prl-default $GATEWAY dev $DEVNAME

ip -6 route add default via fe80::5efe:$GATEWAY dev $DEVNAME

rdisc6 -1 -s fe80::5efe:$MYIP -n  fe80::5efe:$GATEWAY  $DEVNAME

while read LINE; do

    eval $(echo $LINE |grep -e Prefix -e MTU -e DNS|sed 's/ *//g;s/:/=/;s/(.*)//')

done < <(rdisc6 -1 -n  fe80::5efe:$GATEWAY $DEVNAME)

echo $MTU $Prefix $RecursiveDNSserver

IPV6=$(echo $Prefix|sed "s#/#5efe:$MYIP/#")

ip link set dev $DEVNAME mtu $(echo $MTU|sed 's/[a-z]*//g')

echo IPV6 is $IPV6

ip -6 address add $IPV6 dev $DEVNAME