Hello,
We at OpenVPN got reports that after installing Sonicwall VPN Client
our virtual adapter stops working.
https://github.com/OpenVPN/ovpn-dco-win/issues/31
It turned out that the problem is in Citrix DNE Lightweight Filter,
which binds to the lower edge of our NetAdapter-based driver. With
that, our adapter is not visible anymore in “ipconfig /all” and any
attempts to, say, assign an IP address by netsh or IPAPI fail. If I
remove the binding (control panel → network adapter → OpenVPN Data
Channel Offload → Properties → Networking → uncheck
DNE LightWeight Filter) then our adapter is again visible in “ipconfig
/all” and everything works fine.
Is there any way to figure out what Citrix DME does which breaks
adapter functionality? Does it somehow interfere with NetAdapter?
I attached windbg and set Kd_DEFAULT_Mask to 0xFF but do not see
any errors.
Googling tells that this particular driver (Citrix DME) causes many issues.
One workaround I could think of is to set “LowerRange” to “nolower” in
INF file. At the moment I use “ethernet”, as per Jeffrey Tippet’s suggestion
(https://community.osr.com/discussion/comment/296522#Comment_296522).
With “nolower” Citrix DNE cannot bind to the driver and problem
doesn’t occur. Do you think this workaround is good enough?