P0F(1)

NAME
p0f - identify remote systems passively

SYNOPSIS
p0f [ -f file ] [ -i device ] [ -o file ] [ -s file ] [ -vKUtq ] [ 'filter rule' ]

DESCRIPTION
This manual page briefly documents the p0f command.

p0f uses a fingerprinting technique based on information coming from remote host when it tries to establish a connection to your system. Captured packet parameters contain enough information to determine remote OS - and, unlike active scanners (nmap, queSO) - this is done without sending anything to this host.

In short, there are certain TCP/IP flag settings specific for given systems. Usually initial TTL (8 bits), window size (16 bits), maximum segment size (16 bits), don't fragment flag (1 bit), sackOK option (1 bit), nop option (1 bit), window scaling option (8 bits), initial packet size (16 bits) vary from one TCP stack implementation to another, and, combined together, give unique, 67-bit signature for every system.

OPTIONS

-f file
    read fingerprint information from file

-i device
    read packets from device

-s file
    read packets from file

-o file
    write output to file (best with -vt)

-v  verbose mode

-U  do not display unknown signatures

-K  do not display known signatures

-t  add timestamps

-q  quiet mode - do not display banners

FILES

/etc/p0f.fp
    default Operating System fingerprint file

AUTHOR
p0f was written by Michal Zalewski <lcamtuf@coredump.cx>. This man page was written by William Stearns <wstearns@pobox.com>