#!/bin/bash

hostname="HIER ÄNDERN"
# braucht dnsutils 
ip=`nslookup $hostname | awk -F ': ' 'NR==6 { print $2 } '`

#load Kernel Module
modprobe ip_gre

#enable IP-Forwarding - nur das erste mal
#echo 'net.ipv4.ip_forward=1' >> /etc/sysctl.conf
#sysctl -p

#check ip and write to ip.txt
echo $ip > ip.txt

#create tunnel with remote_ip

remote_ip=`cat ip.txt`
ip tunnel add gre1 mode gre local xx.xx.xx.xx remote $remote_ip ttl 255

#set tunnel network
ip addr add 172.20.1.1/30 dev gre1

#set interface gre1 up
ip link set gre1 up

#set routing
ip route add 172.20.1.2 dev gre1
ip route add xx.xx.xx.xx/32 dev gre1

#set arp-proxy (maybe optional)
ip neigh add proxy xx.xx.xx.xx dev eth0

exit