139

I need a cross platform method of determining the MAC address of a computer at run time. For windows the 'wmi' module can be used and the only method under Linux I could find was to run ifconfig and run a regex across its output. I don't like using a package that only works on one OS, and parsing the output of another program doesn't seem very elegant not to mention error prone.

Does anyone know a cross platform method (windows and linux) method to get the MAC address? If not, does anyone know any more elegant methods then those I listed above?

2

17 Answers 17

195

Python 2.5 includes an uuid implementation which (in at least one version) needs the mac address. You can import the mac finding function into your own code easily:

from uuid import getnode as get_mac
mac = get_mac()

The return value is the mac address as 48 bit integer.

10
  • 28
    I just tried this on a Windows box and it works great... except that the laptop I tried it on has 2 NICs (one wireless) and there's no way to determine which MAC it returned. Just a word of warning if you want to use this code. Commented Oct 1, 2008 at 19:55
  • 28
    Just a warning: If you look at the getnode documentation it says that it will return a random long if it fails to detect the mac: "If all attempts to obtain the hardware address fail, we choose a random 48-bit number with its eighth bit set to 1 as recommended in RFC 4122." So check that eighth bit! Commented Feb 1, 2013 at 11:27
  • 31
    hex(mac) to get the familiar hex format of the mac Commented Mar 23, 2014 at 17:29
  • 53
    Or ':'.join(("%012X" % mac)[i:i+2] for i in range(0, 12, 2)) for an uppercase MAC with each byte separated by a colon.
    – tomlogic
    Commented Nov 10, 2014 at 17:21
  • 9
    getnode() returns something different every time I restart my windows 7 laptop.
    – nu everest
    Commented Nov 15, 2014 at 21:52
96

The pure python solution for this problem under Linux to get the MAC for a specific local interface, originally posted as a comment by vishnubob and improved by on Ben Mackey in this activestate recipe

#!/usr/bin/python

import fcntl, socket, struct

def getHwAddr(ifname):
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    info = fcntl.ioctl(s.fileno(), 0x8927,  struct.pack('256s', ifname[:15]))
    return ':'.join(['%02x' % ord(char) for char in info[18:24]])

print getHwAddr('eth0')

This is the Python 3 compatible code:

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import fcntl
import socket
import struct


def getHwAddr(ifname):
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    info = fcntl.ioctl(s.fileno(), 0x8927,  struct.pack('256s', bytes(ifname, 'utf-8')[:15]))
    return ':'.join('%02x' % b for b in info[18:24])


def main():
    print(getHwAddr('enp0s8'))


if __name__ == "__main__":
    main()
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  • 1
    Beautiful, works like a charm! Commented Mar 16, 2022 at 22:51
43

netifaces is a good module to use for getting the mac address (and other addresses). It's crossplatform and makes a bit more sense than using socket or uuid.

import netifaces

netifaces.interfaces()
# ['lo', 'eth0', 'tun2']

netifaces.ifaddresses('eth0')[netifaces.AF_LINK]
# [{'addr': '08:00:27:50:f2:51', 'broadcast': 'ff:ff:ff:ff:ff:ff'}]

1
  • 1
    Used it personally, requires a specific install/compile on each system but works well.
    – Aatch
    Commented Jun 20, 2011 at 17:10
31

Sometimes we have more than one net interface.

A simple method to find out the mac address of a specific interface, is:

def getmac(interface):
    try:
        mac = open('/sys/class/net/'+interface+'/address').readline()
    except:
        mac = "00:00:00:00:00:00"
    return mac[0:17]

to call the method is simple

myMAC = getmac("wlan0")
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  • 6
    Not super useful for OS X or Windows. :| Commented Aug 25, 2017 at 16:21
  • 4
    Perfect for Pis!
    – MikeT
    Commented Oct 23, 2018 at 20:19
  • return mac.strip() may be easier to get rid of the newline ;-) Commented Apr 24, 2022 at 9:56
23

One other thing that you should note is that uuid.getnode() can fake the MAC addr by returning a random 48-bit number which may not be what you are expecting. Also, there's no explicit indication that the MAC address has been faked, but you could detect it by calling getnode() twice and seeing if the result varies. If the same value is returned by both calls, you have the MAC address, otherwise you are getting a faked address.

>>> print uuid.getnode.__doc__
Get the hardware address as a 48-bit positive integer.

    The first time this runs, it may launch a separate program, which could
    be quite slow.  If all attempts to obtain the hardware address fail, we
    choose a random 48-bit number with its eighth bit set to 1 as recommended
    in RFC 4122.
2
  • 8
    Not that the value of the 8th is 1 precisely because it cannot be used by a network card. Just checking this bit is enough to detect whether the address is faked or not. Commented Jul 9, 2012 at 13:10
  • 18
    The check is just done with: if (mac >> 40)%2 : raise OSError, "The system does not seem to have a valid MAC" Commented Jul 9, 2012 at 13:26
9

Using my answer from here: https://stackoverflow.com/a/18031868/2362361

It would be important to know to which iface you want the MAC for since many can exist (bluetooth, several nics, etc.).

This does the job when you know the IP of the iface you need the MAC for, using netifaces (available in PyPI):

import netifaces as nif
def mac_for_ip(ip):
    'Returns a list of MACs for interfaces that have given IP, returns None if not found'
    for i in nif.interfaces():
        addrs = nif.ifaddresses(i)
        try:
            if_mac = addrs[nif.AF_LINK][0]['addr']
            if_ip = addrs[nif.AF_INET][0]['addr']
        except IndexError, KeyError: #ignore ifaces that dont have MAC or IP
            if_mac = if_ip = None
        if if_ip == ip:
            return if_mac
    return None

Testing:

>>> mac_for_ip('169.254.90.191')
'2c:41:38:0a:94:8b'
8

You can do this with psutil which is cross-platform:

import psutil
nics = psutil.net_if_addrs()
print [j.address for j in nics[i] for i in nics if i!="lo" and j.family==17]
1
  • import socket then [addr.address for n in nics for addr in nics[n] if n == 'enp4s0' and addr.family == socket.AF_PACKET] results in ['ab:cd:ef:01:02:03']
    – Donn Lee
    Commented Nov 13, 2019 at 23:33
6

The cross-platform getmac package will work for this, if you don't mind taking on a dependency. It works with Python 2.7+ and 3.4+. It will try many different methods until either getting a address or returning None.

from getmac import get_mac_address
eth_mac = get_mac_address(interface="eth0")
win_mac = get_mac_address(interface="Ethernet 3")
ip_mac = get_mac_address(ip="192.168.0.1")
ip6_mac = get_mac_address(ip6="::1")
host_mac = get_mac_address(hostname="localhost")
updated_mac = get_mac_address(ip="10.0.0.1", network_request=True)

Disclaimer: I am the author of the package.

Update (Jan 14 2019): the package now only supports Python 2.7+ and 3.4+. You can still use an older version of the package if you need to work with an older Python (2.5, 2.6, 3.2, 3.3).

2
  • Standard output for above variables: None None None None 00:00:00:00:00:00 None
    – Napolean
    Commented Dec 30, 2021 at 12:08
  • Those are just examples of usage. You need to replace the arguments with the values applicable to your system, which is very likely why you're getting null results. For example, "eth0" is not applicable to a Windows system, and "Ethernet 3" isn't applicable to a Linux system, but both are included above as examples so you know how to use the library on both platforms. Note: "localhost" will always return "00:00:00:00:00:00". Commented Jan 2, 2022 at 20:43
2

To get the eth0 interface MAC address,

import psutil

nics = psutil.net_if_addrs()['eth0']

for interface in nics:
   if interface.family == 17:
      print(interface.address)
1

Note that you can build your own cross-platform library in python using conditional imports. e.g.

import platform
if platform.system() == 'Linux':
  import LinuxMac
  mac_address = LinuxMac.get_mac_address()
elif platform.system() == 'Windows':
  # etc

This will allow you to use os.system calls or platform-specific libraries.

1
  • 6
    that's not really an answer - just a comment
    – Stefano
    Commented Feb 4, 2019 at 12:08
1

nice actually return a dictionary within the dictionary it returns a list and within the list, it returns a staple. but nics['Ethernet'][0].address iteration solve the problem.

import psutil

nics = psutil.net_if_addrs()

mac_address = nics['Ethernet'][0].address

print(mac_address)
1

This cross-platform code does not 100% work on Windows. This works on Windows:

import psutil
print([(k, addr.address) for k, v in psutil.net_if_addrs().items() for addr in v if addr.family == -1])

Example:

[
    ('Local Area Connection', '01-23-45-67-89-0A'), 
    ('Wireless Network Connection', '23-45-67-89-0A-BC'), 
    ('Bluetooth Network Connection', '45-67-89-0A-BC-DE'), 
    ('isatap.{01ABCDEF-0123-4567-890A-0123456789AB}', '00-00-00-00-00-00-00-01')
]
1

To get the MAC address as a 48-bit int, one can use uuid.getnode():

import uuid

uuid.getnode()
12345678901234

To format this as a colon-separated hex-string, you can use

":".join(f"{b:02x}" for b in uuid.getnode().to_bytes(6))
0b:3a:73:ce:2f:f2

(In Python 3.10 and lower, you'll have to add the byteorder arg: .to_bytes(6, byteorder='big').)

1
  • Just a small comment, you need to add byte orders argument, otherwise you will get TypeError: to_bytes() missing required argument 'byteorder' (pos 2) The proper line looks: ":".join(f"{b:02x}" for b in uuid.getnode().to_bytes(6, "big")) Commented Mar 18 at 13:54
0

I dont know of a unified way, but heres something that you might find useful:

http://www.codeguru.com/Cpp/I-N/network/networkinformation/article.php/c5451

What I would do in this case would be to wrap these up into a function, and based on the OS it would run the proper command, parse as required and return only the MAC address formatted as you want. Its ofcourse all the same, except that you only have to do it once, and it looks cleaner from the main code.

0
-1

Alternatively,

import uuid
mac_id=(':'.join(['{:02x}'.format((uuid.getnode() >> ele) & 0xff)
-2

For Linux let me introduce a shell script that will show the mac address and allows to change it (MAC sniffing).

 ifconfig eth0 | grep HWaddr |cut -dH -f2|cut -d\  -f2
 00:26:6c:df:c3:95

Cut arguements may dffer (I am not an expert) try:

ifconfig etho | grep HWaddr
eth0      Link encap:Ethernet  HWaddr 00:26:6c:df:c3:95  

To change MAC we may do:

ifconfig eth0 down
ifconfig eth0 hw ether 00:80:48:BA:d1:30
ifconfig eth0 up

will change mac address to 00:80:48:BA:d1:30 (temporarily, will restore to actual one upon reboot).

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  • 9
    Does this have to do anything with the question?
    – bot47
    Commented Apr 8, 2016 at 15:44
-9

For Linux you can retrieve the MAC address using a SIOCGIFHWADDR ioctl.

struct ifreq    ifr;
uint8_t         macaddr[6];

if ((s = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP)) < 0)
    return -1;

strcpy(ifr.ifr_name, "eth0");

if (ioctl(s, SIOCGIFHWADDR, (void *)&ifr) == 0) {
    if (ifr.ifr_hwaddr.sa_family == ARPHRD_ETHER) {
        memcpy(macaddr, ifr.ifr_hwaddr.sa_data, 6);
        return 0;
... etc ...

You've tagged the question "python". I don't know of an existing Python module to get this information. You could use ctypes to call the ioctl directly.

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  • 12
    -1 He wants a python solution, so you go and give him the same regurgitated C solution plastered throughout the web.
    – Aatch
    Commented Jun 7, 2011 at 5:00

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