#!/bin/sh create_tun() { name="$1" if ! grep "$name" /proc/net/dev > /dev/null; then ip tuntap add name $name mode tun fi } add_addr() { name="$1" addr="$2" ip addr del "$addr" dev "$name" 2> /dev/null ip addr add "$addr" dev "$name" } create_tun "ogstun4" create_tun "ogstun6" create_tun "ogstun46" add_addr "ogstun4" "176.16.16.1/20" add_addr "ogstun6" "2001:780:44:2000:0:0:0:1/56" add_addr "ogstun46" "176.16.32.1/20" add_addr "ogstun46" "2001:780:44:2100:0:0:0:1/56" ip link set ogstun4 up ip link set ogstun6 up ip link set ogstun46 up