What is the purpose of filterId?

What is the purpose of filterId?
Each filter has GUID, it uniquelly identifies filter, but each filter has filterId yet. In what cases I can use filterId, and what operations I can do using filterId?

klimandr wrote:

What is the purpose of filterId?

Each filter has GUID, it uniquelly identifies filter, but each filter has filterId yet. In what cases I can use filterId, and what operations I can do using filterId?

What kind of a driver are you talking about?  The word “filter” is
aggressively overloaded in the Windows world.

No idea what you mean here. I am not aware of anything named “filterId”.

More detail would be useful,

Peter

If you are referring to the filterID in a WFP driver, then filterID can be thought of as a handle for the filter instance. Yes there is a GUID, but that is not for a specific instance, and it is a pain to lookup and compare GUID’s so for performance a 64-bit ID makes a lot of sense.

Don Burn
Windows Driver Consulting
Website: http://www.windrvr.com

@“Peter_Viscarola_(OSR)” said:
No idea what you mean here. I am not aware of anything named “filterId”.

More detail would be useful,

Peter

@Tim_Roberts said:
What kind of a driver are you talking about? The word “filter” is
aggressively overloaded in the Windows world.

I am refer to filterID in WFP drivers. I did not thought that it is more than one instances named “filter” in windows.
Each filter structure FWPM_FILTER0_ has member filterKey of type GUID and member filterId of type UINT64. We can uniquely identify filter with GUID and with filterId. And in what cases I can use filterId, and what operations I can do using filterId?

Thank you, @Don_Burn.

@Don_Burn said
…Yes there is a GUID, but that is not for a specific instance…

I don’t understand that. Why GUID is not for a specific instance? All instances in wfp has each own GUID.