Openvpn – Cisco AnyConnect VPN via OpenVPN tunnel [Unable to modify IP forwarding table]

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Background: I'm working as a contractor for a small web design agency. We have a particular project / client requires that any updates / development that are performed are done via VPN. The client VPN requires a static IP address, and connects using Cisco AnyConnect. They stipulate that any work performed has to be onsite at the web design agency's location, or we have to VPN into the web design agency's location.

Being a small design agency, the people I'm working for don't have a VPN or static IP address. So, on my personal Linode I setup a VPN using OpenVPN Access Server. I can connect to the VPN server that I setup just fine. I can also access the web login for the clients VPN just fine.

However, once Cisco Anyconnect tries to connect to the clients VPN, I get the error message "The VPN client was unable to modify the IP forwarding table. A VPN connection will not be established. Please restart your computer or device and try again."

I tried on a different computer and I get the same problem. Previously we had the client whitelist my home IP (this is no longer an option) and the VPN connected just fine. Nothing has changed on my end, except for the OpenVPN being in the middle now.

What am I missing here? Is this something that is possible and / or commonplace? I want to go Home Computer > Linode with OpenVPN > Client VPN using Cisco Anyconnect.

Any help and insight would be appreciated. Thanks.

Best Answer

Assuming they require a newer version (3.0 and above) of the AnyConnect Secure Mobility Client, I think the fact you missed is that the only Linux-based platforms supported by the AnyConnect client is 32-bit Ubuntu or RHEL Desktop

Cisco also has a comprehensive compatibility document that describes ASA client platform requirements.

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