ip ro вам в помощь.# Allow TUN interface connections to OpenVPN server
$IPTABLES -A INPUT -i tun+ -j ACCEPT
# Allow TUN interface connections to be forwarded through other interfaces
$IPTABLES -A FORWARD -i tun+ -j ACCEPT
$IPTABLES -A FORWARD -s $OPENVPN_RANGE -d $LAN_RANGE -j ACCEPT
$IPTABLES -A FORWARD -s $LAN_RANGE -d $OPENVPN_RANGE -j ACCEPT 