IP Range to CIDR conversion in Python?

Question

How can I get a CIDR notation representing a range of IP addresses, given the start and end IP addresses of the range, in Python? I can find CIDR to IP Range but cannot find any code for the reverse.

Example of the desired output:

startip = '63.223.64.0'
endip = '63.223.127.255'

return '63.223.64.0/18'

score 37 · Answer 1 · edited Jan 23 '20 at 06:53

37

Starting Python 3.3 the bundled ipaddress can provide what you want. The function summarize_address_range returns an iterator with the networks resulting from the start, end you specify:

>>> import ipaddress
>>> startip = ipaddress.IPv4Address('63.223.64.0')
>>> endip = ipaddress.IPv4Address('63.223.127.255')
>>> [ipaddr for ipaddr in ipaddress.summarize_address_range(startip, endip)]
[IPv4Network('63.223.64.0/18')]

edited Jan 23 '20 at 06:53

Jason

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answered Feb 21 '17 at 15:08

MichielB

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No external dependencies. Love it! – ttimasdf Sep 26 '19 at 10:28
1

Yes.. This should have been the accepted answer.. never the less still very helpful.. – sushanth Sep 15 '20 at 16:26
Only it doesn't give you just 1 cidr, it gives you at least 1. – reubano Feb 07 '23 at 17:13

score 25 · Accepted Answer · edited Jan 23 '20 at 07:06

25

You may use iprange_to_cidrs provided by netaddr module. Example:

pip install netaddr

import netaddr
cidrs = netaddr.iprange_to_cidrs(startip, endip)

Here are the official docs: https://netaddr.readthedocs.io/

edited Jan 23 '20 at 07:06

Jason

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answered Jun 13 '14 at 22:10

ρss

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cidrs = netaddr.ip_range_to_cidrs(ip1 , ip2 ) AttributeError: 'module' object has no attribute 'ip_range_to_cidrs' – Chris Hall Jun 13 '14 at 22:31
1

@ChrisHall Sorry for the typo, I have updated my answer. – ρss Jun 14 '14 at 11:46
2

Here's how to do it in Python3: from ipaddress import ip_address, summarize_address_range; start,end = ip_address(startip), ip_address(endip); return summarize_address_range(start,end). – JJC Mar 09 '16 at 15:55
2

To tidy up @JJC's answer for `python 2.7`................................................................................................. ```from ipaddress import ip_address,summarize_address_range; summarize_address_range(ip_address(unicode(startip)), ip_address(unicode(endip)))``` – Alexander McFarlane Oct 30 '16 at 18:38

reubano · Answer 3 · 2023-02-07T17:46:14.023

If, like me, you want only 1 cidr (instead of multiple cidr's) you'll need to use the spanning_cidr function from either netaddr

pip install netaddr

from netaddr import spanning_cidr
spanning_cidr(startip, endip)

or spanning_cidr

pip install spanning-cidr

from spanning_cidr import spanning_cidr
spanning_cidr([startip, endip])

Here is the difference...

>>> from ipaddress import IPv4Address, summarize_address_range
>>> from netaddr import spanning_cidr
>>>
>>> startip = IPv4Address('63.223.64.0')
>>> endip = IPv4Address('63.224.127.255')
>>> list(summarize_address_range(startip, endip))
[IPv4Network('63.223.64.0/18'),
 IPv4Network('63.223.128.0/17'),
 IPv4Network('63.224.0.0/17')]
>>>
>>> spanning_cidr(startip, endip)
IPv4Network('63.192.0.0/10')

IP Range to CIDR conversion in Python?

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