Posted: Sat May 08, 2010 9:21 Post subject: VPN on WNR3500L with DD-WRT v24-sp2 04/23/10 (14311)
Hi all,
I have a Microsoft Forefront Threat Management Gateway server at home for VPN (among other things), but when I recently upgraded from my Linksys WRT54GL to the Netgear WNR3500L, I lost the ability to connect to the VPN.
When trying to establish a connection, the error message reads: [...]The most common cause for this failure is that at least one Internet device between your computer and the VPN server is not configured to allow Generic Routing Encapsulation (GRE) protocol packets [...]
At first I thought it might be because the stock firmware doesn't allow GRE packets to pass through, so I installed DD-WRT (which I was running on my old WRT54GL) and made sure the VPN Passthrough settings were enabled. However, I am still getting the same error with the Netgear router, while the WRT54GL router with the same settings doesn't cause this error with the VPN connection.
Has anyone encountered a similar issue or is able to help me with this? I copied all the settings exactly from my old router to my new, so I have no clue why it isn't working.
Joined: 31 Jul 2009 Posts: 492 Location: Toronto, ON, CA
Posted: Sat May 08, 2010 13:43 Post subject:
The version of DD-WRT required for your WNR3500L (DD-WRT Kernel 2.6) has a PPTP VPN pass-through bug which your previous router would not encounter since that was using DD-WRT Kernel 2.4. You can try adding and saving the following start-up command code to see if it fixes your VPN issue.
Joined: 31 Jul 2009 Posts: 492 Location: Toronto, ON, CA
Posted: Sat May 08, 2010 15:31 Post subject:
Go to Administration>Commands tab and then in the commands input box type in the code from the previous post. After the commands are entered, press the Save Startup Button and reboot the router. Hopefully this will fix the GRE pass-through bug and allow the VPN to work without the DMZ. If the code does not resolve your issue, try port forwarding the proper VPN port to your server.