所有ip都在子网掩码范围内

Question

I know how to get all the IP in range

from netaddr import iter_iprange
generator = iter_iprange('192.168.1.1', '192.168.255.255', step=1)

What I want is get all the Ip that fix to subnet mask with some IP.

For example I get Ip 2.2.2.2 and mask 255:255:255:0 so I neet to get 255 ip adrresses 2.2.2.2 - 2.2.2.255 , but if subnetmask is 255.255.255.254 I there is no IP that fix to this

How can I get that in python?

Answer 1

You can use IPNetwork:

from netaddr import IPNetwork

ip_addr = '2.2.2.2'
mask = '255.255.255.0'
network = IPNetwork('/'.join([ip_addr, mask]))
generator = network.iter_hosts()

Note: 2.2.2.2/255.255.255.0 is equivalent to CIDR 2.2.2.0/24 , both work for IPNetwork .
Converting to a list you get:

In []:
list(generator)

Out[]:
[IPAddress('2.2.2.1'),
 IPAddress('2.2.2.2'),
 IPAddress('2.2.2.3'),
 ...
 IPAddress('2.2.2.252'),
 IPAddress('2.2.2.253'),
 IPAddress('2.2.2.254')]

According to the netaddr.iter_host documentation:

• for IPv4, the network and broadcast addresses are always excluded. For subnets that contains less than 4 IP addresses /31 and /32 report in a manner per RFC 3021

RFC 3021 says:

In a point-to-point link with a 31-bit subnet mask, the two addresses above MUST be interpreted as host addresses.

So both ip addresses with a mask of 255.255.255.254 are reported:

In []:
mask = '255.255.255.254'
list(IPNetwork('/'.join([ip_addr, mask])).iter_hosts())

Out[]:
[IPAddress('2.2.2.2'), IPAddress('2.2.2.3')]