When trying to connect from a Windows 7 workstation to a PPTP VPN being served by a Server 2003 machine running RRAS I received VPN Error: 720 “A connection to the remote computer might not be established. You might need to change the network settings for this connection.” This would happen after the “Verifying username and password” phase during the “Registering your computer on the network” phase.
Rebuild the TCP/IP stack by opening an elevated command prompt and running the following command:
netsh int ip reset
The Long Story:
I’m running Windows 7 RC and have a PPTP VPN connectoid that connects to a Server 2003 RRAS server. I was able to successfully connect just yesterday but today when I attempt to connect it gets as far as “Registering your computer on the network” and then fails with Error: 720 “A connection to the remote computer might not be established. You might need to change the network settings for this connection.” *sigh* I always hate it when things that worked one day suddenly and with seemingly no reason stop working.
To my knowledge no updates have been applied to the server or to my Windows 7 machine in the time between yesterday and today. First I check to see if my Virtual XP instance can connect to the VPN. I created a new VPN connectoid and was able to connect with no problems using simple default settings.
I then looked at my Windows 7 connectoid’s options and did a little twiddling like disabling “include Windows logon domain” (not sure how that got enabled in the first place) and moved it from PPTP to Automatic (all it does is delay the logon time while it tries to figure out how to connect from among the available options but I figured it was worth a try). Still no luck.
I created a brand new connectoid using the default values for everything and it still gave me Erorr: 720. Fortunately I have a secondary VPN that I use for just such an occasion. It’s via a SonicWALL TZ 180 using the lone SonicWALL Global VPN Client license that came with the firewall. I connected with that so I could check out the RRAS server. The RRAS service was started and the RRAS console showed that all seemed well. I decided to restart the RRAS service from the console and got a little misty that I was saying goodbye to 137 days, 15 hours and 43 seconds of uptime. After the service restart I still received Error: 720. Fare thee well 137 days of uptime… I feel that your death was in vain. =( Looking back, I suppose it was unlikely that the problem was the server since the XP machine could connect, but you never know.
I decided to try the sweeping “netsh int ip reset >> resetIP.log” to reset the TCP/IP stack. The log simply stated:
Reseting Global, OK!
Reseting Interface, OK!
Reseting Unicast Address, OK!
Restart the computer to complete this action.
Super. I restarted, tried again and voilá!! I was able to connect with no problems! Farewell, VPN Error 720. As to what caused this issue in the first place… I’ll never know.