List of IP addresses/hostnames from local network in Python

Question

How can I get a list of the IP addresses or host names from a local network easily in Python?

It would be best if it was multi-platform, but it needs to work on Mac

Answer 1

I have collected the following functionality from some other threads and it works for me in Ubuntu.

import os
import socket    
import multiprocessing
import subprocess
import os


def pinger(job_q, results_q):
    """
    Do Ping
    :param job_q:
    :param results_q:
    :return:
    """
    DEVNULL = open(os.devnull, 'w')
    while True:

        ip = job_q.get()

        if ip is None:
            break

        try:
            subprocess.check_call(['ping', '-c1', ip],
                                  stdout=DEVNULL)
            results_q.put(ip)
        except:
            pass


def get_my_ip():
    """
    Find my IP address
    :return:
    """
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    s.connect(("8.8.8.8", 80))
    ip = s.getsockname()[0]
    s.close()
    return ip


def map_network(pool_size=255):
    """
    Maps the network
    :param pool_size: amount of parallel ping processes
    :return: list of valid ip addresses
    """

    ip_list = list()

    # get my IP and compose a base like 192.168.1.xxx
    ip_parts = get_my_ip().split('.')
    base_ip = ip_parts[0] + '.' + ip_parts[1] + '.' + ip_parts[2] + '.'

    # prepare the jobs queue
    jobs = multiprocessing.Queue()
    results = multiprocessing.Queue()

    pool = [multiprocessing.Process(target=pinger, args=(jobs, results)) for i in range(pool_size)]

    for p in pool:
        p.start()

    # cue hte ping processes
    for i in range(1, 255):
        jobs.put(base_ip + '{0}'.format(i))

    for p in pool:
        jobs.put(None)

    for p in pool:
        p.join()

    # collect he results
    while not results.empty():
        ip = results.get()
        ip_list.append(ip)

    return ip_list


if __name__ == '__main__':

    print('Mapping...')
    lst = map_network()
    print(lst)

Answer 2

Update: The script is now located on github.

I wrote a small python script, that leverages scapy's arping().

Answer 3

I have done following code to get the IP of MAC known device. This can be modified accordingly to obtain all IPs with some string manipulation. Hope this will help you.

#running windows cmd line  statement and put output into a string
cmd_out = os.popen("arp -a").read()
line_arr = cmd_out.split('\n')
line_count = len(line_arr)


#search in all lines for ip
for i in range(0, line_count):
    y = line_arr[i]
    z = y.find(mac_address)

    #if mac address is found then get the ip using regex matching
    if z > 0:
        ip_out= re.search('[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+', y, re.M | re.I)

Answer 4

If you know the names of your computers you can use:

import socket
IP1 = socket.gethostbyname(socket.gethostname()) # local IP adress of your computer
IP2 = socket.gethostbyname('name_of_your_computer') # IP adress of remote computer

Otherwise you will have to scan for all the IP addresses that follow the same mask as your local computer (IP1), as stated in another answer.

Answer 5

I found this network scanner in python article and wrote this short code. It does what you want! You do however need to know accessible ports for your devices. Port 22 is ssh standard and what I am using. I suppose you could loop over all ports. Some defaults are:

linux: [20, 21, 22, 23, 25, 80, 111, 443, 445, 631, 993, 995]
windows: [135, 137, 138, 139, 445]
mac: [22, 445, 548, 631]

import socket

def connect(hostname, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    socket.setdefaulttimeout(1)
    result = sock.connect_ex((hostname, port))
    sock.close()
    return result == 0

for i in range(0,255):
    res = connect("192.168.1."+str(i), 22)
    if res:
        print("Device found at: ", "192.168.1."+str(i) + ":"+str(22))

Answer 6

For OSX (and Linux), a simple solution is to use either os.popen or os.system and run the arp -a command.

For example:

devices = []
for device in os.popen('arp -a'): devices.append(device)

This will give you a list of the devices on your local network.