Fixing error 720 on an SsTP VPN

Fixing Error 720 on a Server 2008/2008 R2 Secure Socket Tunnelling Protocol (SSTP) VPN.

I’m unsure how common this problem is, or how specific to me… but it took a lot of figuring out, so in the hope that it helps someone else…

I have Server 2008 R2 running the Routing and Remote Access role to serve as an SSTP (Secure Socket Tunnelling Protocol) VPN server so my Windows 7 laptop can connect to it. I recently changed my hardware router for a different router, and ever since, was receiving “Error 720: “ when trying to connect to the VPN.

After a dismally long time trying pointless other things, I fixed the problem by going to the Routing and Remote Access settings (run rrasmgmt.msc on the VPN server), right clicking on the server name and selecting Properties, navigating to the IPv4 tab, and changing “Dynamic Host Configuration Protocol (DHCP)” to “Static address pool”, and entering a valid IP range in there.

 

These are the errors I was experiencing prior to this:

Error 720: A connection to the remote computer could not be established. You might need to change the network settings for this connection.

CoId={F06425E8-D193-48B8-A55C-A2774D53B684}: The user  <username> connected to port VPN0-127 has been disconnected because no  network protocols were successfully negotiated.

Log Name:      System
	Source:         RemoteAccess
	Date:           9/12/2009 9:45:53 AM
	Event ID:      20253
	Task Category: None
	Level:         Error
	Keywords:      Classic
	User:          N/A
	Computer:       <removed>
	Description:
	CoId={8101141A-FCD0-477D-9EC4-E3B2C4CDE6AB}: The user  <username> connected to port VPN0-127 has been disconnected because no  network protocols were successfully negotiated.
	Event Xml:
	<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
	<System>
	<Provider  Name="RemoteAccess" />
	<EventID  Qualifiers="0">20253</EventID>
	<Level>2</Level>
	<Task>0</Task>
	<Keywords>0x80000000000000</Keywords>
	<TimeCreated  SystemTime="2009-12-08T23:45:53.000000000Z" />
	<EventRecordID>4011</EventRecordID>
	<Channel>System</Channel>
	<Computer><computer name> </Computer>
	<Security />
	</System>
	<EventData>
	<Data>{8101141A-FCD0-477D-9EC4-E3B2C4CDE6AB}</Data>
	<Data><username></Data>
	<Data>VPN0-127</Data>
	</EventData>
</Event>

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Updated about 5 mths, 8 days ago (August 30, 2011). Know a better answer? Let us know!

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User submitted comments:

Alan Singfield, about 1 yr, 8 mths ago
Monday May 10, 2010 11:14 AM

Thanks, this solved my problem - it looks like the DHCP doesn't seem to work very well.

John Vajda, about 1 yr, 8 mths ago
Thursday May 13, 2010 5:41 AM

Wow, MANY THANKS for taking the time to post this. It solved my problem.

I too had installed a new router, and my vpn connection started failing with an error code of 720. Event ID 20253 appeared in the System event log of the vpn server as described above. I could tell that the Windows 7 pptp (or actually sstp) server was the culprit, not the client. Interestingly, when I reverted to troubleshooting by using old router, the problem persisted.

In Windows 7, there is no rrasmgmt.msc snapin. Simply go into Control Panel -> Network and Internet -> Network and Sharing Center -> Change Adapter settings. Select "Incoming Connections", right-click and go into Properties, and select a static address pool for IPv4.

Ed A, about 1 yr, 7 mths ago
Thursday June 10, 2010 7:14 PM

Just found this by chance after hours searching on Google and going through tons of bad advice. Thank you!

Marek, about 11 mths, 2 days ago
Sunday March 6, 2011 1:00 PM

Many thanks, I spending days searching on Google and MS forum

Michael, about 10 mths, 18 days ago
Monday March 21, 2011 12:24 AM

Excellent. Fixed my problem. Why can't the error log say it's having trouble allocating an IP address, rather than being so obtuse, eh?

Mohsen Heydari, about 8 mths, 27 days ago
Thursday May 12, 2011 9:25 AM

Thanks a lot! i couldn't fix my problem without that info

Drmaster, about 6 mths, 3 hrs ago
Tuesday August 9, 2011 9:13 AM

YES!!!! It is WORK!!!! Thanks!!!!
(win 2008 server r2 x64 instaled on vmware work-on, TMG)

hernadi, about 4 mths, 14 days ago
Sunday September 25, 2011 9:46 AM

To fix error 720 :
C:windowssystem32sfc.exe /scannow, and then restart.

hernadi, about 4 mths, 14 days ago
Sunday September 25, 2011 9:48 AM

To fix error 720 :
C:windows system32 sfc.exe /scannow, and then restart.

Rico, about 1 mth, 10 hrs ago
Friday January 6, 2012 2:03 AM

You are a Champ, it worked for me too :-)

Thanks a million.

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