I am experiencing a wierd problem with my firewall drivers during a routine test on Windows7. I am using TDI and NDIS IM drivers ( Windows 7 ) and I am running an apache benchmark test agains the W7 machine that has an IIS installed, from a linux.
I am downloading index.html 2000 times on 1000 connections.
When my TDI driver is installed, some downloading requests fail. The TDI driver is started at boot, but the order in PNP_TDI lists my driver the last one. My TDI driver calls IoAttachDevice on devicetcp, udp, ip and rawip.
I have disabled all filtering in my TDI, calling IoSkipCurrentIrpStackLocation and calling IoCallDriver. Same result.
If my driver is started later, after an admin has logged in, the problem dissapears. The primary suspect for this is the load order of the driver, which is more confusing since the GroupOrderList/PNP_TDI lists my driver the last.