L2TP iptables port forward
- by The_cobra666
Hi all,
I'm setting up port forwarding for an L2TP VPN connection to the local Windows 2003 VPN server. The router is a simpel Debian machine with iptables. The VPN server works perfect. But I cannot log in from the WAN. I'm missing something.
The VPN server is using a pre-shared key (L2TP) and give's out an IP in the range: 192.168.3.0. Local network range is 192.168.2.0/24
I added the route: with route add -net 192.168.3.0 netmask 255.255.255.240 gw 192.168.2.13 (the vpn server)
iptables -t nat -A PREROUTING -p udp --dport 1701 -i eth0 -j DNAT --to 192.168.2.13
iptables -A FORWARD -p udp --dport 1701 -j ACCEPT
iptables -t nat -A PREROUTING -p udp --dport 500 -i eth0 -j DNAT --to 192.168.2.13
iptables -A FORWARD -p udp --dport 500 -j ACCEPT
iptables -t nat -A PREROUTING -p udp --dport 4500 -i eth0 -j DNAT --to 192.168.2.13
iptables -A FORWARD -p udp --dport 4500 -j ACCEPT
iptables -t nat -A PREROUTING -p 50 -j DNAT --to 192.168.2.13
iptables -A FORWARD -p 50 -j ACCEPT
iptables -t nat -A PREROUTING -p 51 -j DNAT --to 192.168.2.13
iptables -A FORWARD -p 51 -j ACCEPT
The whole iptables script is (without the line's from above):
echo 1 > /proc/sys/net/ipv4/ip_forward
echo 1 > /proc/sys/net/ipv4/tcp_syncookies
#Flush table's
iptables -F INPUT
iptables -F OUTPUT
iptables -F FORWARD
iptables -t nat -F
#Drop traffic
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT
#verkeer naar buiten toe laten en nat aanzetten
iptables -A FORWARD -i eth0 -o eth1 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -i eth1 -o eth0 -j ACCEPT
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
#RDP forward voor windows servers
iptables -t nat -A PREROUTING -p tcp --dport 3389 -i eth0 -j DNAT --to 192.168.2.10:3389
iptables -A FORWARD -p tcp --dport 3389 -j ACCEPT
iptables -t nat -A PREROUTING -p tcp --dport 3340 -i eth0 -j DNAT --to 192.168.2.12:3340
iptables -A FORWARD -p tcp --dport 3340 -j ACCEPT
#toestaan SSH verkeer
iptables -t nat -A PREROUTING -p tcp --dport 22 -i eth0 -j DNAT --to-destination 192.168.2.1
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
#toestaan verkeer loopback
iptables -A INPUT -i lo -j ACCEPT
#toestaan lokaal netwerk
iptables -A INPUT -i eth1 -j ACCEPT
#accepteren established traffic
iptables -A INPUT -i eth0 --match state --state RELATED,ESTABLISHED -j ACCEPT
#droppen ICMP boodschappen
iptables -A INPUT -p icmp -i eth0 -m limit --limit 10/minute -j ACCEPT
iptables -A INPUT -p icmp -i eth0 -j REJECT
ifconfig eth1 192.168.2.1/24
ifconfig eth0 XXXXXXXXXXXXX/30
ifconfig eth0 up
ifconfig eth1 up
route add default gw XXXXXXXXXXXXXXXXXXX
route add -net 192.168.3.0 netmask 255.255.255.240 gw 192.168.2.13
