DelphiFAQ Home Search:

My local network does not work since VPN install


comments19 comments. Current rating: 5 stars (11 votes). Leave comments and/ or rate it.


I have a local network and one of those machines has the Cisco VPN client installed. Now VNC fails to connect to that machine with the VPN client, even if the VPN client is not running. I also notice trouble using ftp to outside sites, again, without being on the VPN.
It seems as if I was behind some firewall but I cannot find any. I turned off the Windows Firewall completely already.


The reason is a certain driver that Cisco's VPN client installed on your machine. It is called 'Deterministic Network Enhancer'. This driver is active even if you do not load the VPN client.
You can see it in the control panel, click on 'network connections' and there right-click on your ethernet card.
You could in theory disable or remove this enhancer there and you would instantly be able to VNC into your machine again, however, this requires a reboot and afterwards your VPN won't work anymore.

Luckily there is a solution around.
  1. Start the VPN client
  2. In the tray, right-click on the icon
  3. Uncheck "Stateful Firewall (Always On)
VPN and VNC at the same time
Now your local network will work again. You could even make this change temporarily, e.g. remove the check, VNC into the machine, then add the check again, while your VNC connection remains alive.

Content-type: text/html


You are on page 2 of 2, other pages: 1 [2]
2009-09-17, 09:58:19
anonymous from Canada  
I love hidden Firewalls on my PC. Thanks.
2010-03-07, 11:35:14

my local network got disconnect when connect VNC

please help me
2012-11-04, 22:25:03
GENSYS from India  
Its excellent help!!! Thyank you very much.. Was wasting my working days due to this reason only. I was not in a postion to reinstal windows.. Excellent help.. Thnx Buddy!!
2013-02-04, 03:18:26
anonymous from Korea (R)  
Thank you also save my computer issue
You are on page 2 of 2, other pages: 1 [2]



NEW: Optional: Register   Login
Email address (not necessary):

Rate as
Hide my email when showing my comment.
Please notify me once a day about new comments on this topic.
Please provide a valid email address if you select this option, or post under a registered account.

Show city and country
Show country only
Hide my location
You can mark text as 'quoted' by putting [quote] .. [/quote] around it.
Please type in the code:

Please do not post inappropriate pictures. Inappropriate pictures include pictures of minors and nudity.
The owner of this web site reserves the right to delete such material.

photo Add a picture: