Some embodiments provide a novel method for monitoring network requests from a machine. The method captures the network request at various layers of a protocol stack. At a first layer of a protocol stack, the method tags a packet related to the network request with a tag value, maps the tag value to a set of tuples associated with the packet, and sends a first set of data related to the packet to a security engine. At a second layer of the network stack, the method determines whether the packet has been modified through the network stack, and sends an updated second set of data to the security engine when the packet has been modified.