Cidrize

IP address parsing for humans.

Cidrize takes IP address inputs that people tend to use in practice, validates them, and converts them to objects.

Intelligently parses IPv4/IPv6 addresses, CIDRs, ranges, and wildcard matches to attempt return a valid list of IP addresses.

The cidrize() function does all the work trying to parse IP addresses correctly.

Installation

You can install cidrize via Pip:

pip install cidrize

Dependencies

Cidrize is basically a thin veneer around netaddr to provide a human layer for parsing IP addresses.

Usage

Supported input formats

Input is very flexible and can be of any of the following formats:

192.0.2.18
192.0.20.64/26
192.0.2.80-192.0.2.85
192.0.2.170-175
192.0.2.8[0-5]
192.0.2.[5678]

Hyphenated ranges do not need to form a CIDR block but the starting number must be of lower value than the end. The netaddr module does most of the heavy lifting for us here.

Unsupported formats

Network mask (e.g. 192.0.2.0 255.255.255.0) and host mask (aka reverse mask, 192.0.2.0 0.0.0.255) notation are not accepted at this time.

The cidrize function returns a list of consolidated netaddr.IPNetwork objects. By default parsing exceptions will raise a CidrizeError (with default argument of raise_errors=True). You may pass raise_errors=False to cause exceptions to be stripped and the error text will be returned as a list. This is intended for use with scripts or APIs where receiving exceptions would not be preferred.

The module may also be run as a script for debugging purposes.

The cidrize function

Fire up your trusty old Python interpreter and follow along!

>>> from cidrize import cidrize

Old-fashioned CIDR

>>> cidrize("1.2.3.4")
[IPNetwork('1.2.3.4/32')]

Hyphenated range (default, strict=False)

>>> cidrize("2.4.6.8-2.4.6.80")
[IPNetwork('2.4.6.0/25')]

Hyphenated range strict (strict=True)

>>> cidrize("2.4.6.8-2.4.6.80", strict=True)
[IPNetwork('2.4.6.8/29'), IPNetwork('2.4.6.16/28'),
IPNetwork('2.4.6.32/27'), IPNetwork('2.4.6.64/28'),
IPNetwork('2.4.6.80/32')]

Wildcard

You may provide wildcards using asterisks. This is limited to the 4th and final octet only:

>>> cidrize("15.63.148.*")
[IPNetwork('15.63.148.0/24')]

Bracketed range

>>> cidrize("21.43.180.1[40-99]")
[IPNetwork('21.43.180.140/30'), IPNetwork('21.43.180.144/28'),
IPNetwork('21.43.180.160/27'), IPNetwork('21.43.180.192/29')]

Bad!

Bad CIDR prefixes are rejected outright:

>>> cidrize("1.2.3.38/40")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "cidrize.py", line 145, in cidrize
    raise CidrizeError(err)
cidrize.CidrizeError: CIDR prefix /40 out of range for IPv4!

Wack range?!

Ranges must always start from lower to upper bound, or this happens:

>>> cidrize("1.2.3.4-0")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "cidrize.py", line 145, in cidrize
    raise CidrizeError(err)
cidrize.CidrizeError: lower bound IP greater than upper bound!

Cidr Tool

The cidrize package also comes with the cidr command, which has two basic operations.

Simple output:

% cidr 1.2.3.4/30
1.2.3.4/30

Verbose output:

% cidr -v 1.2.3.4/30
Spanning CIDR:          1.2.3.4/30
Block Start/Network:    1.2.3.4
1st host:               1.2.3.5
Gateway:                1.2.3.6
Block End/Broadcast:    1.2.3.7
DQ Mask:                255.255.255.252
Cisco ACL Mask:         0.0.0.3
# of hosts:             2
Explicit CIDR blocks:   1.2.3.4/30

And that's that!

Contributing

This project uses conventional commits for automated versioning and changelog generation. Please format your commit messages accordingly:

• fix: <description> - Patch release (bug fixes)
• feat: <description> - Minor release (new features)
• feat!: <description> or BREAKING CHANGE: - Major release (breaking changes)
• docs:, chore:, ci:, test:, refactor:, perf:, build: - No release (housekeeping)

License

Cidrize is licensed under the BSD 3-Clause License. Please see LICENSE.md for the details.