如何在 Python 3 中生成随机 IPv6 子网

Question

我有一个现有的 IPv6 地址块。如何使用 Python 在此块中生成随机 /64 网络，最好不使用任何外部库？

例如，您可以从fd00::/8 Unique Local Address (ULA) 块开始生成一个随机的私有 ipv6 网络。

Answer 1

正如@Ron Maupin 在他们对 OP 答案的评论中所指出的，这是一个使用正确数量的随机位的解决方案：

#! /usr/bin/env python3
"""IPv6 ULA generation."""

from ipaddress import IPv6Network
from random import getrandbits


__all__ = ['get_ula_network']


ULA_BASE = IPv6Network("fd00::/8")


def get_ula_network() -> IPv6Network:
    """Generates a random ULA network."""

    random_suffix = getrandbits(40) << 80
    base_address = ULA_BASE.network_address + random_suffix
    return IPv6Network((base_address, 48))

您可以通过以下方式驱动上述/64 网络：

>>> network = get_ula_network()
>>> subnets = list(network.subnets(new_prefix=64))
>>> len(subnets)
65536
>>> 

Answer 2

您可以使用标准的random 和ipaddress 模块来执行此操作。短版：

from ipaddress import IPv6Network
import random

ula = IPv6Network("fd00::/8")
random_network = IPv6Network((
    ula.network_address + (random.getrandbits(64 - ula.prefixlen) << 64 ),
    64))

带解释的加长版：

from ipaddress import IPv6Network
import random

# Start from the ula address block
ula = IPv6Network("fd00::/8")

# Get a random bitstring the size of the number of bits we can randomise.
# This is the number of bits reserved for the network (64) minus the number of bits
# already used in the address block we start from (8).
random_bits = random.getrandbits(64 - ula.prefixlen)

# Bitshift those bits 64 times to the left, so the last 64 bits are zero.
random_address_suffix = random_bits << 64

# Add those bits to the network address of the block we start from
# and create a new IPv6 network with the modified address and prefix 64
random_network = IPv6Network((
    ula.network_address + random_address_suffix,
    64))