List of IP addresses/hostnames from local network

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 OS X first, then others follow.

Edit: By local I mean all active addresses within a local network, such as 192.168.xxx.xxx.

So, if the IP address of my computer (within the local network) is 192.168.1.1, and I have three other connected computers, I would want it to return the IP addresses 192.168.1.2, 192.168.1.3, 192.168.1.4, and possibly their hostnames.

Answer 1

Try:

import socket

print ([ip for ip in socket.gethostbyname_ex(socket.gethostname())[2] if not ip.startswith("127.")][:1])

Answer 2

If by "local" you mean on the same network segment, then you have to perform the following steps:

1. Determine your own IP address
2. Determine your own netmask
3. Determine the network range
4. Scan all the addresses (except the lowest, which is your network address and the highest, which is your broadcast address).
5. Use your DNS's reverse lookup to determine the hostname for IP addresses which respond to your scan.

Or you can just let Python execute nmap externally and pipe the results back into your program.

Answer 3

Here is a small tool scanip that will help you to get all ip addresses and their corresponding mac addresses in the network (Works on Linux). This is the link for scanip (Ip and Mac scanner) written in python. https://pypi.python.org/pypi/scanip/1.0

You can also download it using pip install scanip on linux and to use it , create a test file in python and use it like this-

import scanip.scanip

scanip.scanip.start_scan()

and run this program . All the ip and their corresponding mac addresses in the LAN will be shown in the terminal.

Answer 4

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 5

Update: The script is now located on github.

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

Answer 6

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.