Joined: 15 Feb 2011
|Posted: Tue Feb 15, 2011 14:35 Post subject: LAN to WAN VPN problems
I am having a lot of trouble making connections to outside VPN servers from machines behind my WZR-HP-G300NH router running DD-WRT v24-sp2. The setup is as follows:
The problem is as follows: I try to make a connection to VPN servers at my workplace from a machine (any one, Mac or PC) behind my router. I consistently get error 619 and the connection fails.
The DSL modem was originally a 2wire 2701HG-G, but for troubleshooting purposes I replaced it with a "straight" modem. (The 2wire is locked by my ISP and cannot have its routing, DHCP etc. functions disabled, i.e., it can't be put into bridge mode. I swapped it out to exclude it as the source of my problem.) So the modem currently connected is a plain old Thomson SpeedTouch ST516v6 in bridge mode. But the problem is the same in both cases.
HOWEVER, as soon as I put one of my machines in the DMZ, the connection succeeds, no problems at all!
Also, when I had the 2wire modem-router attached, I could plug a machine directly into it (effectively bypassing my DD-WRT router) and the VPN connection would succeed. (I can't do this with the SpeedTouch, obviously, because it doesn't have any spare Ethernet ports, being a plain vanilla modem.)
So it seems to me that all of this implies that the DD-WRT router is not directing VPN traffic properly.
Another bit of information: I seem to remember having a similar problem YEARS ago that I solved, I think, by disabling loopback in DD-WRT (on a WRT54G). But I can't find that setting in v24-sp2.
Finally, I have tried toggling STP and "Filter WAN NAT redirection". Checking Filter WAN NAT redirection seemed to work, for a moment, as I was able to make a connection once or twice, but then it went back to throwing error 619. Since then, nothing seems to work, i.e., I can't make a connection no matter what I do. Maybe the one or two times I was able to connect it was a traffic fluke. I haven't changed much else in the DD-WRT settings since setting up this router a few days ago.
I should also mention that I have tried to connect to 3 different VPN servers. Two are workplace PPTP servers. The third is a PPTP server I set up on an offsite DD-WRT router. I can connect to the third VPN no problem. It's the others that don't work. They all used to work back when I used a WRT54G and another Buffalo router (a WHP-something).
Thanks very much in advance.