Ubuntu Manpage: arp-fingerprint - Fingerprint a system using ARP

NAME

       arp-fingerprint - Fingerprint a system using ARP

SYNOPSIS

       arp-fingerprint [options] target

       The  target  should  be  specified as a single IP address or hostname.  You cannot specify
       multiple targets, IP networks or ranges.

       If you use an IP address for the target, you can use the -o option to pass  the  --numeric
       option  to arp-scan, which will prevent it from attempting DNS lookups.  This can speed up
       the fingerprinting process, especially on systems with a slow or faulty DNS configuration.

DESCRIPTION

arp-fingerprint fingerprints the specified target host using the ARP protocol.

It sends various different types of ARP request to the target, and records which types it
responds to. From this, it constructs a fingerprint string consisting of "1" where the
target responded and "0" where it did not. An example of a fingerprint string is
01000100000. This fingerprint string is then used to lookup the likely target operating
system.

Many of the fingerprint strings are shared by several operating systems, so there is not
always a one-to-one mapping between fingerprint strings and operating systems. Also the
fact that a system's fingerprint matches a certain operating system (or list of operating
systems) does not necessarily mean that the system being fingerprinted is that operating
system, although it is quite likely. This is because the list of operating systems is not
exhaustive; it is just what I have discovered to date, and there are bound to be operating
systems that are not listed.

The ARP fingerprint of a system is generally a function of that system's kernel (although
it is possible for the ARP function to be implemented in user space, it almost never is).

Sometimes, an operating system can give different fingerprints depending on the
configuration. An example is Linux, which will respond to a non-local source IP address
if that IP is routed through the interface being tested. This is both good and bad: on
one hand it makes the fingerprinting task more complex; but on the other, it can allow
some aspects of the system configuration to be determined.

Sometimes the fact that two different operating systems share a common ARP fingerprint
string points to a re-use of networking code. One example of this is Windows NT and
FreeBSD.

arp-fingerprint uses arp-scan to send the ARP requests and receive the replies.

There are other methods that can be used to fingerprint a system using arp-scan which can
be used in addition to arp-fingerprint. These additional methods are not included in arp-
fingerprint either because they are likely to cause disruption to the target system, or
because they require knowledge of the target's configuration that may not always be
available.

arp-fingerprint is still being developed, and the results should not be relied on. As most
of the ARP requests that it sends are non-standard, it is possible that it may disrupt
some systems, so caution is advised.

If you find a system that arp-fingerprint reports as UNKNOWN, and you know what operating
system it is running, could you please send details of the operating system and
fingerprint to arp-scan@nta-monitor.com so I can include it in future versions. Please
include the exact version of the operating system if you know it, as fingerprints
sometimes change between versions.

OPTIONS

       -h     Display a brief usage message and exit.

       -v     Display verbose progress messages.

       -o <option-string>
              Pass  specified  options  to  arp-scan.  You  need to enclose the options string in
              quotes if it contains spaces. e.g.  -o "-I eth1".  The commonly  used  options  are
              --interface (-I) and --numeric (-N).

       -l     Fingerprint  all  hosts on the local network. You do not need to specify any target
              hosts if this option is given.

EXAMPLES

       $ arp-fingerprint 192.168.0.1
       192.168.0.1   01000100000     Linux 2.2, 2.4, 2.6

       $ arp-fingerprint -o "-N -I eth1" 192.168.0.202
       192.168.0.202 11110100000     FreeBSD 5.3, Win98, WinME, NT4, 2000, XP, 2003

NOTES

       arp-fingerprint is implemented in Perl, so you need to have the Perl interpreter installed
       on your system to use it.

AUTHOR

       Roy Hills <Roy.Hills@nta-monitor.com>