Poptop VPN and Iptables/UDP Broadcast Problems **FIXED**

[JazzSax006]

I've setup poptop and am using it to create a vpn for windows xp clients.  My XP test box can connect fine and communicate with the rest of the network, but when I try to use a program that broadcasts UDP packets, my iptables firewall is blocking them.  The subnet of the VPN and the rest of my LAN is 192.168.1.0/24, but the iptables logs show that the packets being blocked originate from 10.0.0.3, which is the IP address the XP box has on the network it is connecting from.  Does anyone have any suggestions to get around this problem?  Here's an example log entry:

Code: Select all

Feb  2 15:32:38 bobbyz UDP Rejected IN=ppp0 OUT= MAC= SRC=10.0.0.3 DST=255.255.255.255 LEN=48 TOS=0x00 PREC=0x00 TTL=128 ID=17706 PROTO=UDP SPT=6111 DPT=6111 LEN=28

Edit: I've been told that the problem is windows cannot handle udp broadcasts over different subnets and that I would need a GRE tunnel to get this working. If this is the case, does anyone know of any GRE tunneling solutions that are free and could connect my XP box to my linux box?

Edit: Okay, I finally got everything working by using openvpn in tap bridging mode between my windows XP box and my linux box. So far no problems whatsoever. Way to go, openvpn!

[n3mo]

Sometimes ago I read something about vpn between linux and windows using openswan, I only made vpn beween linux machines, and I don't know if it will work for for you, but you can take a look at www.openswan.org

[JazzSax006]

Thank you for the reply. I actually just got everything working late last night. I meant to edit my original post again but was too tired. The thing that finally worked was using openvpn with a tap bridge. I always figured openvpn's windows support would probably be reminiscent of the old CIPE days where the driver was flaky to say the least, but openvpn's driver actually seems quite stable. Kudos to the openvpn team for an awesome piece of software