
TAP interface), or completely uninstall it as a whole. The solution is to either disable the NDIS filter for the affecting interfaces (e.g.

This NDIS driver seems to be incompatible with any MTU other than 1500. Investigating further, it turned out the so called Kaspersky Anti-Virus NDIS 6 Filter is to blame. Furthermore, OpenVPN process and the whole tunnel could come to a halt. On these clients, once a packet reaches the MTU, further packets could be dropped. That however, is likely not going work on windows clients running Kaspersky products. In a previous post, I talked about how to optimize OpenVPN by adjusting the MTU to your links. That goes for the Firewall, Safe Browsing, SSL Hijacking, and of course their newest addition, Secure Connection… While I do believe they provide the best anti-virus in the market, I am not a fan of most of their other products. I cross-posted here to save some poor soul a lot of searching.I like Kaspersky anti-virus, and I use it regularly… (Not on my own PC mind you, but on the clients)

I basically only found out you have to re-enable the "Web-Anti-Virus" feature so you can disable the automatic re-enabling of add-ons in Firefox.

