PRADS is a Passive Real-time Asset Detection System.

PRADS employs digital fingerprints to recognize services on the wire,
and can be used to map your network and monitor for changes in real
time.

Real-time passive traffic analysis will also let you detect assets
that are just connected to the network for a short period of time,
since PRADS can glean useful information from every packet.

PRADS aims to be the one-stop-shop for passive asset detection, and
currently does MAC lookups, TCP and UDP OS fingerprinting as well as
client and service application matching and a connection state table.
Various output plugins include logfile and FIFO and make PRADS a
useful replacement for p0f, pads and sancp.

PRADS was built from the ground up for a small footprint and modern
networks with IPv6 and gigabits of throughput.