Network objects provide access to a live network. There are several forms of network objects, depending on the protocol layer specified for access to the underlying network, in addition to the facilities provided by the host operating system. Use of some network objects requires special access privileges where noted. Generally, network objects provide an entrypoint into the live network at a particular protocol layer (e.g. link, raw IP, UDP, etc) and with a particular access mode (read-only, write-only, or read-write). Some network objects provide specialized facilities such as filtering or promiscuous access (i.e. the pcap/bpf network object) or group membership (i.e. UDP/IP multicast). The C++ class Network is provided as a base class from which specific network objects are derived. Three network objects are currently supported: pcap/bpf, raw IP, and UDP/IP. Each are described below.