FIX: The VPN client failed to establish a connection

by Vlad Constantinescu
Vlad Constantinescu
Vlad Constantinescu
VPN Expert & Privacy Advocate
Vlad might have a degree in Animal Husbandry and Livestock Management, but he's currently rocking anything software related, ranging from testing programs to writing in-depth reviews about them.... read more
Affiliate Disclosure
  • If you're using Cisco AnyConnect, you may have encountered the infamous VPN client failed to establish a connection error, preventing employees from remotely connecting to their workplace.
  • Although this issue fixes itself more often than not, sometimes you might need to step into action to solve it. Discover 6 easy workarounds.
  • Visit the Security VPN section to see how to enhance your online security with a VPN.
  • Check out our Cisco Troubleshooting Hub to fix more Cisco VPN errors.
the vpn client failed to establish a connection

If you’re using Cisco AnyConnect, you may have encountered the infamous VPN client failed to establish a connection error. More often than not, this issue solves itself, but sometimes it may take a bit of elbow grease to put the wheels in motion.

Although a VPN client, Cisco AnyConnect isn’t your regular privacy-protection security tool. In fact, this service was developed to help remote workers access the enterprise network and share company resources in a safe, secure manner.

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How to fix Cisco AnyConnect’s connection error?

1. Restart your PC

Restarting not only your PC, but also the app itself, your router, and possibly your modem too can have quite the effect in this situation. It’s well-known that your PC builds upon on cached data, but so does your router.

Thus, giving them a chance to refresh their internal configuration, discard old, outdated data, and acquire new one might work wonders. There’s a good reason why restarting is the first suggestion of most customer support agents.

Furthermore, you could try uninstalling the AnyConnect VPN client and perform a fresh install. It’s not exactly uncommon for updates to render perfectly functional features unusable.

2. Flush your DNS

    1. Press the Win key on your keyboard
    2. Type CMD
    3. Right-click the Command Prompt icon
    4. Select Run as administratorflush DNS servers in Windows 10
    5. Type the following commands, in this precise order, one by one:
      • ipconfig /flushdns
        ipconfig /registerdns
        ipconfig /release
        ipconfig /renew
        netsh winsock reset
    6. Restart your computer
    7. Launch Cisco AnyConnect
    8. Check if the connection problem still persists


If restarting your PC and router didn’t do the trick, manually forcing your PC to discard old cached DNS and acquire a new set of DNS servers might just be enough to put things back in order.

3. Disable Wi-Fi hotspot

If you have a Wi-Fi hotspot up and running on your PC, it would be wise to turn it off and checking if the problem still persists.

Reportedly, this issue occurs more frequently for Windows 7 PC users, but it might’ve slipped on later versions of this operating system, as well.

4. Disable ICS

  1. Hit the Win key
  2. Type Services
  3. Select the Services app from the resultsServices Start menu
  4. Scroll down to Internet Connection Sharing (ICS)
  5. Right-click it and select Properties
  6. Click the Startup type combo menu
  7. Select Disabled from the menuDisable ICS
  8. Click Apply and OK
  9. Restart your PC
  10. Check if the issue still persists

5. Change adapter settings

  1. Press the Win key on your keyboard
  2. Type Ethernet settingsEthernet settings in start menu
  3. Access the Ethernet settings section
  4. Click the Change adapter options buttonThe change adapter options button
  5. Right-click your active connection and select Properties
  6. Go to the Sharing tab
  7. Make sure the sharing option is not checked (uncheck it if necessary)Disable Internet Sharing
  8. Restart your PC
  9. Check if the VPN client failed to establish a connection error still persists

6. Check your firewall/antivirus settings

  1. Press the Win key
  2. Type Firewall
  3. Select the Firewall & Network protection option
  4. Click the Allow an app through firewall button
  5. Press the Change settings button
  6. Look for Cisco AnyConnect in the list
  7. If you can’t find it, use the Allow another app button
  8. Make sure the Private and Public boxes are both checked
  9. Click OK
  10. Check your antivirus for any signs of blocking Cisco AnyConnect
  11. Add Cisco AnyConnect to your antivirus’ exception list
  12. Restart your computer
  13. Check if the VPN connection error is still there

Some users reported that certain antivirus software solutions block some programs by default. Therefore, it’s not enough to leave the program (Cisco AnyConnect) as it is.

What you’ll need to do is open the antivirus program and add the VPN to a trusted list.

Final thoughts on fixing VPNs failing to establish connections

All things considered, if you’re having a difficult time getting your VPN to establish a connection, you might want to try troubleshooting the issue manually.

More often than not, the situation fixes itself. However, sometimes you might need to step into action and perform certain steps such as restarting your PC, clearing your cache, flushing your DNS, or even disabling Windows services temporarily.

Your connection is not secure - websites you visit can find out your details:

  • Your IP
  • Your IP Address:

Companies can sell this information, alongside your location and internet provider name, and profit from it by serving targeted ads or monitoring your data usage.

Use a VPN to protect your privacy and secure your connection.

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