installing NDIS lightweight filter requires OS reboot

Question

I am trying to develop a tool that dynamically loads an NDIS 6.0 lightweight filter and unloads it later on. I have run into a problem. Some systems require reboot after the filter installation. (INetCfgClassSetup:Install returns 0x4A020 NETCFG_S_REBOOT). The driver does not get loaded. Yet other systems load driver right away and everything works just fine. The lightweight filter is almost identical to the sample at src\network\ndis\filter in WinDDK. My assumption is that the lightweight filter is supposed to load without requiring OS reboot. Is this a valid assumption? If yes, how do I troubleshoot the system that requires reboot?

It turned out all the systems that return NETCFG_S_REBOOT do not have TESTSIGNING ON or kernel debugger attached. So the driver did not work on those systems at all (even after the reboot). So the problem is solved. Apparently NDIS lightweight filter does not require OS reboot after all. — glagolig

Evgenii Gostiukhin Evgenii Gostiukhin · Accepted Answer · 2012-05-03T23:09:14

When you add new ndis filter, system must pause and restart all driver stack. Maybe some other filter prevent to restart driver stack (for example firewall ndis filter).

installing NDIS lightweight filter requires OS reboot

1 Answers