What Iptables rules need I to forward a windows remote desktop connection?

Question

I have this situation:

network mask. 255.255.255.0

• router/gateway: Ubuntu server (only command line, no gui) with internal lan ip 192.168.0.2 and a dynamic dns on the external ip

• Windows pc on 192.168.0.1 with RDP (remote desktop connection) enabled on 3389

I want to forward the RDP service on the external address: how can i do that?

What are the iptables rules I need to connect to my Windows pc from the outside world?

Solution 1

So just giving you this rule probably won't be enough. Here's why: I'm not sure if (a) it'll work right (haven't tested it) and (b) if it does work it'll do more than work - it'll probably forward RDP packets to ANY machines in your network. The dilemma is, how to get the right IP address for the -d nnn.nnn.nnn.nnn/nnn argument. So... buyer beware; if 0/0 works it'll probably work to ALL machines behind your router.

Anyways, here you go:

iptables -A FORWARD -p tcp -s 0/0 -d 0/0 --destination-port 3389 -j ACCEPT

Here's some good reading on iptables: http://oceanpark.com/notes/firewall_example.html

Regards,
-pbr

Solution 2

You need to create a destination NAT (DNAT) rule to map the RDP (3389) on your internet connection's IP address to your internal systems IP address. Something like this:

iptables -t nat -A PREROUTING -i $EXTIF -p tcp --dport 3389 -j DNAT --to 192.168.0.1:3389

Replace $EXTIF with your external ethernet adapter (eth0, etc1,...). You can read this for more information (or if I got something wrong in this example, I didn't test it)

Comments

[apelliciari]

3389, as i wrote before. Yes, i need only 3389 udp, but i don't know how to "construct" iptables rules for that forwarding.. i need a hint, googled it but i haven't found a clear explanation :(

[apelliciari]

i need that iptable rule! i don't know the right syntax to forward 3389 tcp and udp to that computer from the server

[pbr]

Also you might have to repeat the line with "-p udp" instead of "-p tcp"

[mike]

using yolinux.com/TUTORIALS/LinuxTutorialIptablesNetworkGateway.ht‌​ml you can go over your basics and start your model for your system. not using a standard router and tring to use a linux server is great but you i need to know your set up before i can give you the syntax but this website should clear up setting your iptables and ipchains for port forwarding