12-28-2012 09:35 AM - edited 02-21-2020 06:35 PM
Hi,
I'm using the AnyConnect client to login to our VPN. AnyConnect 3.1.00495 is running on Windows 7 home premium. Before Christmas, it was working fine. I've not made any changes to hardware or the home network. How do I remedy the error Unable to modify the IP forwarding table?
01-01-2013 03:04 PM
The VPN client was unable to modify the IP forwarding table. A VPN connection will not be established. Please restart your computer or device, then try again.
Description AnyConnect failed to apply all the VPN configuration settings to the endpoint IP forwarding table. A VPN connection is not permitted because this failure could compromise both its security and operation. This error is unrecoverable.
Recommended User Response Restart your computer or device, then try a new VPN connection. If the problem persists, run DART. (See Using DART to Gather Troubleshooting Information.) Report the error to your organization's technical support and include the DART bundle.
Recommended Administrator Response Open a case with the Cisco Technical Assistance Center (TAC) and include the DART bundle.
found it here
02-13-2014 09:19 AM
I would also recommend checking to make sure the client is not receiving the same IP address from the Cisco appliance that they have received from the network that is local to them.
I.E.
local workstations ip address is 192.168.1.10
and the vpn is trying to assign the client 192.168.1.10
thus creating a conflict. Many different ways of resolving this problem, first obvious one would be fix your firewall so it does not pass out such a common home networked ip address.
10-29-2017 04:29 AM
Applies at least to MacOS: You should also check, that VPN does not give same DNS server IP that you have manually entered via Network settings for your adapter. Same error occurs also in that case.
01-30-2020 05:56 AM - edited 01-30-2020 05:56 AM
I had this problem while working from home this week
AnyConnect Error: Unable To Verify IP Forwarding Table Modifications
Pete
12-07-2020 01:37 PM - edited 12-07-2020 01:39 PM
I encountered this issue today and resolved very quickly with the help of IT support.
Issue:
Cisco Anyconnect VPN fails to establish VPN connection and troughs error "The VPN client was unable to modify the IP forwarding table. A VPN connection will not be established. Please restart your computer or device, then try again."
Solution:
Delete the following files and restart the PC(This is for windows 10 laptop).
C:\ProgramData\Cisco\Cisco AnyConnect Secure Mobility Client\routechangesv4.bin
C:\ProgramData\Cisco\Cisco AnyConnect Secure Mobility Client\routechangesv6.bin
01-04-2021 11:36 AM
Worked for me, thanks!
You will need to run as administrator to del the files.
To do so - Search for “cmd”, then right click on “Command Prompt” and select “Run as Administrator”.
07-19-2021 03:20 AM
Thanks.
05-03-2022 08:47 AM
This solution also worked for me. Thanks.
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