AnyConnect 4.2.04018 randomly drops and reconnects with DD-WRT router

harisundara.rajan · ‎01-19-2017

I have a laptop with Windows 7 64bit installed, and the 4.2.04018 version of AnyConnect to connect to my employer's VPN.

When at home, I connect via buffalotech dot com site /products/airstation-highpower-n600-gigabit-dual-band-open-source-dd-wrt-wireless-rou

Every so often the VPN stops. The WiFi connection itself is stable.

Most of the times, the lock icon from the AnyConnect icon in the tray doesn't even disappear. However, I can tell because my SSH connection breaks, then a few seconds later the green box "VPN Reconnecting" shows up on the bottom right of my screen.

Any ideas how I can even start troubleshooting? Obviously I don't have access to the server or anything, but speaking with my employer's IT support shows they don't see any wierd behavior on their end. Also, when I am on a wired connection, when I am connected to my Unifi access point or when I am connected to my library's WiFi for example, the VPN connectivity is relatively stable, making me think there's something going on with my dd-wrt and my laptop.

Any suggestions on how I can start debugging and what the problem might be?

Thanks

Rahul Govindan · ‎01-19-2017

I would start with running a continuous ping to your gateway and an internet address and see the bahavior is when the traffic stops working. Maybe even a Wireshark capture on your adapter if you are not sending too much traffic. Another troubleshooting aspect is capturing the Anyconnect Diagnostic bundle (DART) on your machine after the issue happens. This would give your IT staff enough information to look at or even open a case with Cisco to understand if this is expected behavior. Most of the cases I have seen this is with spotty wifi connectvitiy causing Anyconnect to not receive responses to keepalives from the headend. Procedure to collect DART is here:

https://supportforums.cisco.com/document/12747756/how-collect-dart-bundle-anyconnect