DHCPv6 PD Revoke Script / DenisKlimek

#!/bin/bash

RACONF="/etc/radvd.conf"

tmp=`sudo ifconfig eth1 | grep global | awk -F " " '{ print $2 }'`
if [ "$tmp" ]; then
    echo "Active IPv6 Prefix found"
    CURRENT_INET6=${tmp::-1}
fi
if [ "$CURRENT_INET6" ]; then
    echo $CURRENT_INET6 > ~/CURRENT_INET6
    if [ -f ~/LAST_INET6 ]; then
        LAST_INET6=`cat ~/LAST_INET6`
        if [ "$CURRENT_INET6" != "$LAST_INET6" ]; then
            sed '$d' $RACONF > /var/tmp/radvd.conf
            mv /var/tmp/radvd.conf $RACONF
            echo "Different IPv6 Prefix found"
            echo "    prefix "$LAST_INET6"/64 {" >> $RACONF
            echo "        AdvOnLink on;" >> $RACONF
            echo "        AdvPreferredLifetime 0;" >> $RACONF
            echo "        AdvAutonomous on;" >> $RACONF
            echo "        AdvValidLifetime 0;" >> $RACONF
            echo "    };" >> $RACONF
            echo "};" >> $RACONF
            /etc/init.d/radvd reload
            echo $CURRENT_INET6 > ~/LAST_INET6
        else
            echo "Same prefix as before"
        fi
    else
        echo "Copying..."
        cp ~/CURRENT_INET6 ~/LAST_INET6
    fi
fi

exit 0