.\" Copyright (C) Roy Hills, NTA Monitor Ltd.

.\"

.\" Copying and distribution of this file, with or without modification,

.\" are permitted in any medium without royalty provided the copyright

.\" notice and this notice are preserved.

.\"

.TH GET-OUI 1 "August 13, 2016"

.\" Please adjust this date whenever revising the man page.

.SH NAME

get-oui \- Fetch the arp-scan OUI file from the IEEE website

.SH SYNOPSIS

.B get-oui

.RI [ options ]

.SH DESCRIPTION

.B get-oui

fetches the Ethernet OUI file from the IEEE website, and saves it in the

format used by arp-scan.

.PP

The OUI file contains all of the OUIs (Organizationally Unique Identifiers)

that have been registered with IEEE. Each OUI entry in the file specifies

the first 24-bits of the 48-bit Ethernet hardware address, leaving the

remaining 24-bits for use by the registering organisation. For example

the OUI entry "080020", registered to Sun Microsystems, applies to any

Ethernet hardware address from

.I 08:00:20:00:00:00

to

.I 08:00:20:ff:ff:ff

inclusive. Each OUI assignment represents a total of 2^24 (16,777,216)

Ethernet addresses.

.PP

Every major Ethernet hardware vendor registers an OUI for their equipment,

and larger vendors will need to register more than one. For example, 3Com

have a total of 37 OUI entries. Organisations that only produce a small

number of Ethernet devices will often obtain an IAB registration instead.

See

.BR get-iab (1)

for details.

.PP

This script can be used to update the

.B arp-scan

OUI file from the latest data on the IEEE website. Most of the Ethernet

addresses in use belong to an OUI registration, so this is the most

important of the files that

.B arp-scan

uses to decode Ethernet hardware addresses. You should therefore run

.B get-oui

occasionally to keep the

.B arp-scan

OUI file up to date.

.PP

The OUI data is fetched from the URL

.I http://standards-oui.ieee.org/oui/oui.txt

and the output file is saved to the file

.I ieee-oui.txt

in the current directory. The URL to fetch the data from can be changed with

the

.B -u

option, and the output file name can be changed with the

.B -f

option.

.PP

The

.I ieee-oui.txt

file that is produced by this script is used by

.B arp-scan

to determine the Ethernet card vendor from its hardware address.

.PP

The directory that

.B arp-scan

will look for the

.I ieee-oui.txt

file depends on the options used when it was built. If it was

built using the default options, then it will look in

.IR /usr/local/share/arp-scan .

.SH OPTIONS

.TP

.B -h

Display a brief usage message and exit.

.TP

.B -f <fn>

Write the output to the specified file instead of the default

.I ieee-oui.txt.

.TP

.B -u <URL>

Use the specified URL to fetch the raw OUI data from instead of the default

.I http://standards-oui.ieee.org/oui/oui.txt.

.TP

.B -v

Display verbose progress messages.

.SH FILES

.TP

.I ieee-oui.txt

The default output file.

.SH EXAMPLES

.nf

$ get-oui -v

Renaming ieee-oui.txt to ieee-oui.txt.bak

Fetching OUI data from http://standards-oui.ieee.org/oui/oui.txt

Fetched 3467133 bytes

Opening output file ieee-oui.txt

22402 OUI entries written to file ieee-oui.txt

.fi

.SH NOTES

.B get-oui

is implemented in Perl, so you need to have the Perl interpreter installed on

your system to use it.

.PP

.B get-oui

uses the

.I LWP::UserAgent

Perl module to fetch the data from the IEEE website. You must have this module

installed on your system for

it to work. This module is available on most distributions, often called

.IR libwww-perl .

It is also available in source form from CPAN.

.PP

You can use a proxy server by defining the

.I http_proxy

environment variable.

.SH AUTHOR

Roy Hills <[email protected]>

.SH "SEE ALSO"

.TP

.BR arp-scan (1)

.TP

.BR get-iab (1)

.TP

.BR arp-fingerprint (1)

.PP

.I http://www.nta-monitor.com/wiki/

The arp-scan wiki page.