Python 3: create a list of possible ip addresses from a CIDR notation

Question

I have been handed the task of creating a function in python (3.1) that will take a CIDR notation and return the list of possible ip addresses. I have looked around python.org and found this: http://docs.python.org/dev/py3k/library/ipaddr.html

but i haven't seen anything that will fill this need... I would be very grateful for any assistance anyone cares to kick my way. thanks in advance. :-)

Might want to go back and accept some answers to your questions if they were helpful... — TM., Dec 21 '09 at 21:52
I have used IPy (http://c0re.23.nu/c0de/IPy/) on Python 2.x, and now am in the process of porting it to Python 3. I will post a link as an answer once I am done. — AJ., Dec 21 '09 at 22:26
@AJ: IPy is also a good choice, but I recommended netaddr because I like it better. :) — jathanism, Dec 22 '09 at 01:10
Update: I have submitted a new version of IPy to its current maintainer for review. Given the holidays, I'm not sure when this will be released, but I will post a link once it is. — AJ., Dec 24 '09 at 19:21

score 71 · Answer 1 · answered Dec 06 '18 at 09:37

71

In Python 3 as simple as

>>> import ipaddress
>>> [str(ip) for ip in ipaddress.IPv4Network('192.0.2.0/28')]
['192.0.2.0', '192.0.2.1', '192.0.2.2',
'192.0.2.3', '192.0.2.4', '192.0.2.5',
'192.0.2.6', '192.0.2.7', '192.0.2.8',
'192.0.2.9', '192.0.2.10', '192.0.2.11',
'192.0.2.12', '192.0.2.13', '192.0.2.14',
'192.0.2.15']

answered Dec 06 '18 at 09:37

Petr Javorik

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this works directly on the python3 terminal but how about in a .py file?? – Tony Jan 04 '21 at 18:25
@Tony The first two lines of this answer can go into a .py file, minus the >>> at the head of each line. In the second line, you should assign the list to a variable which you can then view or do other operations on. If you put [str(ip) for ip in ipaddress.IPv4Network('192.0.2.0/28')] as-is into a file and then run it, there will be no output. But assign it to a variable like ip_list = [str(ip) for ip in ipaddress.IPv4Network('192.0.2.0/28')], then you can print(ip_list) for example to see the list. – CptSupermrkt Feb 11 '21 at 05:16
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Please note that this answer provides a list of addresses which include both the network address (192.0.2.0) and the broadcast address (192.0.2.15) which are not usable for assigning to a host. This is correct behavior for Python, but could lead to confusion with other stakeholders if they are not familiar with networking. – iLoveTux Oct 12 '21 at 22:43

score 51 · Answer 2 · answered Dec 21 '09 at 21:50

51

If you aren't married to using the built-in module, there is a project called netaddr that is the best module I have used for working with IP networks.

Have a look at the IP Tutorial which illustrates how easy it is working with networks and discerning their IPs. Simple example:

>>> from netaddr import IPNetwork
>>> for ip in IPNetwork('192.0.2.0/23'):
...    print '%s' % ip
...
192.0.2.0
192.0.2.1
192.0.2.2
192.0.2.3
...
192.0.3.252
192.0.3.253
192.0.3.254
192.0.3.255

answered Dec 21 '09 at 21:50

jathanism

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interesting but how is the mapping done? is there a deterministic formula that maps the CIDR networks to the single IP addresses? Or one needs a database to do the mapping? – ℕʘʘḆḽḘ Jun 20 '18 at 12:27

jfly · Answer 3 · 2018-08-29T02:17:33.573

13

I would prefer to do a little math rather than to install an external module, no one has the same taste with me?

#!/usr/bin/env python
# python cidr.py 192.168.1.1/24

import sys, struct, socket

(ip, cidr) = sys.argv[1].split('/')
cidr = int(cidr) 
host_bits = 32 - cidr
i = struct.unpack('>I', socket.inet_aton(ip))[0] # note the endianness
start = (i >> host_bits) << host_bits # clear the host bits
end = start | ((1 << host_bits) - 1)

# excludes the first and last address in the subnet
for i in range(start, end):
    print(socket.inet_ntoa(struct.pack('>I',i)))

edited Aug 29 '18 at 02:17

answered May 18 '17 at 09:12

jfly

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Note that this excludes the broadcast address, which may or may not be what you want. Remove the `-1` when computing "end" to include it. – Peter Feb 01 '18 at 15:38
@Peter, removing the `-1` only works on even IP addresses (e.g. where the 4th octet ends in an even number). Add `end += 1` as the line just after subtracting 1. – rabidang3ls Oct 04 '18 at 20:42
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@jfky could you please explain this math? – drjackild Dec 16 '20 at 14:35

score 3 · Answer 4 · answered Dec 21 '09 at 19:43

3

Have you checked out iptools? It seems to be a fairly good fit.

answered Dec 21 '09 at 19:43

Hank Gay

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Given that it seems to not support Python 2.3, it would probably require at least a nominal amount of effort to support Python 3.1. – ephemient Dec 21 '09 at 20:00
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I've updated iptools to support Python 2.3, 2.5, 2.6 and 3.1. – bd808 Jan 01 '10 at 06:40

score 2 · Answer 5 · answered Jun 17 '21 at 13:12

We can get this by using ipaddress lib of Python if you are not interested in playing with python logics. Else above solutions are enough.

import ipaddress
  
def get_ip_from_subnet(ip_subnet):

    ips= ipaddress.ip_network(ip_subnet)
    ip_list=[str(ip) for ip in ips]
    return ip_list

ip_subnet= "192.168.2.0/24"
print(get_ip_from_subnet(ip_subnet))

ephemient · Answer 6 · 2009-12-21T20:20:06.367

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It's not in the documentation, but browsing the source suggests that ipaddr implements __iter__ and iterhosts, which is exactly what you want.

Err, nevermind.

It looks like ipaddr.py was added to stdlib in 3.1 beta, but removed by 3.1 rc.
I was looking at the sources from the original ipaddr.py, which seems to have evolved separately from the copy at python.org.

You could just bundle the latter.

edited Dec 21 '09 at 20:20

answered Dec 21 '09 at 20:06

ephemient

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score 0 · Answer 7 · answered Sep 23 '16 at 06:06

Below code will generate range of IPs on providing IP and subnet. Expand the CIDR notation like(255.255.255.0)

from netaddr import *

def getFirstIp(ipAddress,subnet):
  ipBin = IPNetwork(ipAddress).ip.bits().split('.')
  subBin = IPNetwork(subnet).ip.bits().split('.')
  zipped = zip(ipBin,subBin)
  netIdList = []
  for octets in zipped:
    netIdList.append(''.join(str(b) for b in (map((lambda x: int(x[0])*int(x[1])),zip(list(octets[0]),list(octets[1]))))))
  firstIp = ''
  firstIp = '.'.join(str(int(oct,2)) for oct in netIdList)
  return firstIp


def getLastIp(ipAddress,subnet):
  ipBin = IPNetwork(ipAddress).ip.bits().split('.')
  subBin = IPNetwork(subnet).ip.bits().split('.')
  #print ipBin
  #print subBin
  revsubBin = []
  for octets in subBin:
    revB = ''.join('1' if(b == '0') else '0' for b in octets)
    revsubBin.append(revB)
  zipped = zip(ipBin,revsubBin)
  netIdList = []
  for octets in zipped:
    netIdList.append(''.join(str(b) for b in (map((lambda x: 0 if(int(x[0]) == 0 and int(x[1]) == 0) else 1),zip(list(octets[0]),list(octets[1]))))))
  #print netIdList
  lastIp = ''
  lastIp = '.'.join(str(int(oct,2)) for oct in netIdList)
  return lastIp

def getRangeOfIps(firstIp,lastIp):
  start= int(IPAddress(firstIp))
  end = int(IPAddress(lastIp))
  ipList = []
  for ip in range(start,end+1):
    ipList.append(str(IPAddress(ip)))
  return ipList

def manipulateIP():
 firstIp = getFirstIp(ipAddress,subnet)
 lastIp = getLastIp(ipAddress,subnet)
 ipList = getRangeOfIps(firstIp,lastIp)  
 print ipList

Stephen Blum · Answer 8 · 2019-03-01T21:22:06.243

Generate all Public IP Addresses given a CIDR

https://github.com/stephenlb/geo-ip will generate a list of Valid IP Public Addresses including Localities.

'1.0.0.0/8' to '191.0.0.0/8' are the valid public IP Address range exclusive of the reserved Private IP Addresses.

IP Generator

Generates a JSON dump of IP Addresses and associated Geo information. Note that the valid public IP Address range is from '1.0.0.0/8' to '191.0.0.0/8' excluding the reserved Private IP Address ranges shown lower down in this readme.

docker build -t geo-ip .
docker run -e IPRANGE='54.0.0.0/30' geo-ip               ## a few IPs
docker run -e IPRANGE='54.0.0.0/26' geo-ip               ## a few more IPs
docker run -e IPRANGE='54.0.0.0/16' geo-ip               ## a lot more IPs
docker run -e IPRANGE='0.0.0.0/0'   geo-ip               ## ALL IPs ( slooooowwwwww )
docker run -e IPRANGE='0.0.0.0/0'   geo-ip > geo-ip.json ## ALL IPs saved to JSON File
docker run geo-ip

A little faster option for scanning all valid public addresses:

for i in $(seq 1 191); do \
    docker run -e IPRANGE="$i.0.0.0/8" geo-ip; \
    sleep 1; \ 
done

This prints less than 4,228,250,625 JSON lines to STDOUT. Here is an example of one of the lines:

{"city": "Palo Alto", "ip": "0.0.0.0", "longitude": -122.1274,
 "continent": "North America", "continent_code": "NA",
 "state": "California", "country": "United States", "latitude": 37.418,
 "iso_code": "US", "state_code": "CA", "aso": "PubNub",
 "asn": "11404", "zip_code": "94107"}

Private and Reserved IP Range

The dockerfile in the repo above will exclude non-usable IP addresses following the guide from the wikipedia article: https://en.wikipedia.org/wiki/Reserved_IP_addresses

MaxMind Geo IP

The dockerfile imports a free public Database provided by https://www.maxmind.com/en/home

Python 3: create a list of possible ip addresses from a CIDR notation

8 Answers8

Generate all Public IP Addresses given a CIDR

IP Generator

Private and Reserved IP Range

MaxMind Geo IP

Linked