|I am learning more about the cPacket deep packet analyzer/packet sniffer. The device uses an output filter, which I understand can filter incoming IP packets based on IP source address, destination address, keyword, phone number, etc. The device also has a pre filter, which I understand is used to speed up the entire packet sniffing process.|
My question is, what is a packet pre filter? As far as I can tell, it is the exact same thing as an output filter. Is this true? If so, why have two of the same filters?
If possible, can someone define and/or describe what is a pre filter in the context of packet sniffers?