[deluxe79]

Hi all!

Since I'm a big fan of dd-wrt, I would like to make a small contribution. Keep ut the good work Brainslayer.

Assuming you have a working VPN connection to the PPTP server implemented in dd-wrt.

Issue: How to get broadcast IP belonging one subnet to additionally broadcast on an another subnet? The answer is routing.

For example, say you're hosting a multiplayer game like Warcraft 3 that utilieses the broadcast IP of the underlying subnetmask the host computer is running on. When you do a cmd -> ipconfig on the hosting computer, you'd most likely see that the subnetmask on your local area connection is 255.255.255.0. If you do the same on a client computer connected to the PPTP server, you'd see that the subnetmask of the VPN connection differs from the local area connection. Local area connection at subnetmask 255.255.255.0 and VPN connection at 255.255.255.255. This means that the VPN connection is on a different subnet.

So the PPTP server uses subnetmask 255.255.255.255 and your game is hosting on subnet 255.255.255.0. Because of this, the VPN connection will never receive the messages broadcasted from the broadcasting IP on the other subnet. Thats why the clients can't find the host on games that uses broadcast IP to announce their presents.

Let's say your router IP is 10.0.0.1. You have setup PPTP server to accept 10 VPN connections in the range of 10.0.0.50-59 (Use outside DHCP range!). In a subnet with subnetmask 255.255.255.0 you have a total of 254 IP-addresses available. (10.0.0.1 - 10.0.0.254). 255 is reserved for broadcasting on the respective subnet. Only difference is that as mentioned, the IP addresses that is reserved for the PPTP server are on a different subnetmask, thus another subnet.

Ok, how to get around this issue, the answer is pretty simple. The only thing you will have to do is to add a static route, under Basic Setup -> Advanced Routing.

In Dest. LAN IP: 10.0.0.1
Subnetmask : 255.255.255.255
Gateway : 0.0.0.0
Interface : LAN/WLAN

Now we have created a static route that routes a connection between those subnets.

What it basically does is routing all traffic on the subnet with subnetmask 255.255.255.255 to the subnet with subnetmask 255.255.255.0.

Now clients can see the host, and you're ready to play.

Hope this helps solve someones problem.

Frank T.

[wcarlson40]

Wow, thanks for the info, I will have to give this a try. Maybe this should be added to the Wiki somewhere under VPN stuff....

[x-demon]

Sorry for up... But - what i must type in destination ip? LAN, External(real), Or WAN ip?

[OBI66]

Sorry, but i'm still not getting it.

[OBI66]

anyone?

[iurgnahz]

my router works on pptp server.a romote pc can dial in,and we can ping each other,but when we play Warcraft III, we cannot find each other in Lan.

[iurgnahz]

dd-wrt v24sp1
Buffalo WHR-HP-G54

[xeoncross]

yep this is just the problem that I am having. The PC's stay on different subnets despite the above settings.

[ianmacg]

I flashed my linksys router with dd-wrt and setup the PPTP server exactly as described in the tutorial, as well as added the static route as specified here. Clients can connect to my VPN and pinging works all around. But Starcraft and Warcraft still do not advertise the games across the VPN.

Here is my routing table:

Routing Table Entry List
Destination LAN NET Subnet Mask Gateway Interface
192.168.2.1 255.255.255.255 0.0.0.0 LAN & WLAN
192.168.2.0 255.255.255.0 0.0.0.0 LAN & WLAN
24.10.171.0 255.255.255.0 0.0.0.0 WAN
169.254.0.0 255.255.0.0 0.0.0.0 LAN & WLAN
0.0.0.0 0.0.0.0 24.10.171.1 WAN

Any help would be much appreciated

[bpapa9013]

But wouldn't you have to setup a route in the opposite direction as well for the clients to talk to the host?

[jmcgeejr]

Bump to this, I didn't see it when I posted mine. Anyone here have any luck?

[tarad10]

Routing, by definition, segments broadcast domains. Simple routing won't work here. I have gotten this to work using the pre-sp2 builds of DD-WRT. I am using a WRT54Gv4 with DD-WRT v24-sp2 (01/10/09) vpn. The secret here is bcrelay. In v24-sp1 pptpd was not compiled with bcrelay support.

You should not have to add any routes into the routing table for this to work as long as you have a dd-wrt firmware that supports bcrelay. You can tell if bcrelay is supported by simply typing bcrelay from a telnet/ssh session with your router. If it fusses at you it is not installed (if it doesn't fuss at you manually kill the second instance of bcrelay you probably just started). It is also a good idea to turn on ip forwarding with this command: "echo 1 > /proc/sys/net/ipv4/ip_forward". If you still can't get it to work, pm me or reply to post.

If anyone out there is trying to get netbios name shares to work, I am pretty sure you need a WINS server. If you have a big enough flash, you can install samba on your router. If not you can run a separate linux box with samba, and inject the pptp interface on the remote side with the address of the linux box for the wins server: "ms-wins #.#.#.#" in the options.pptpd file. If you are really desperate, you can install it in Windows XP with cygwin. Obviously if you are running Windows Server you can set this up pretty simply as well. Your local machines will also have to use this WINS server.

[OKK77]

[pock]

Interesting.. I had tried a few months back to do something fimilar on extrenal networks.. Two Remote Locations, but being able to access each other with internal addresses.. 192.168.1.x would be able to access say a webserver at an Remote location by using 192.168.0.x I was able to get ping through the tunnel to the vpn server/list but I couldn't acces any other machines on the network.. broadcasts didn't work either as I wasn't able to play LAN games with the other network

I hope this isn't to far off topic, but I wonder if such a thing is possible with the dd-wrt firmware and if so, has anyone done it?

[tarad10]