Created
December 20, 2012 11:23
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A simple python script converts a Classless Inter-Domain Routing (CIDR)-formatted IP address into an IP range and netmask.
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#!/usr/bin/env python | |
# python subnet.py 200.100.33.65/26 | |
import sys | |
# Get address string and CIDR string from command line | |
(addrString, cidrString) = sys.argv[1].split('/') | |
# Split address into octets and turn CIDR into int | |
addr = addrString.split('.') | |
cidr = int(cidrString) | |
# Initialize the netmask and calculate based on CIDR mask | |
mask = [0, 0, 0, 0] | |
for i in range(cidr): | |
mask[i/8] = mask[i/8] + (1 << (7 - i % 8)) | |
# Initialize net and binary and netmask with addr to get network | |
net = [] | |
for i in range(4): | |
net.append(int(addr[i]) & mask[i]) | |
# Duplicate net into broad array, gather host bits, and generate broadcast | |
broad = list(net) | |
brange = 32 - cidr | |
for i in range(brange): | |
broad[3 - i/8] = broad[3 - i/8] + (1 << (i % 8)) | |
# Print information, mapping integer lists to strings for easy printing | |
print "Address: " , addrString | |
print "Netmask: " , ".".join(map(str, mask)) | |
print "Network: " , ".".join(map(str, net)) | |
print "Broadcast: " , ".".join(map(str, broad)) |
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Thanks for that, it have rescue much time for me! :)
But i use Python3 and no Python2 atm, because i have some little errors.
I have just only addet a / to the calculations and addet the new () syntax for the prints.
old:
mask[i/8] = mask[i/8] + (1 << (7 - i % 8))
print "Address: " , addrString
new:
mask[i//8] = mask[i//8] + (1 << (7 - i % 8))
print("Address: " , addrString)
For Python3 users:
`
import sys
(addrString, cidrString) = sys.argv[1].split('/')
addr = addrString.split('.')
cidr = int(cidrString)
mask = [0, 0, 0, 0]
for i in range(cidr):
mask[i//8] = mask[i//8] + (1 << (7 - i % 8))
net = []
for i in range(4):
net.append(int(addr[i]) & mask[i])
broad = list(net)
brange = 32 - cidr
for i in range(brange):
broad[3 - i//8] = broad[3 - i//8] + (1 << (i % 8))
print("Address: " , addrString)
print("Netmask: " , ".".join(map(str, mask)))
print("Network: " , ".".join(map(str, net)))
print("Broadcast: " , ".".join(map(str, broad)))`