Write a program to demonstrate sub-netting and find the sub-net masks.

Write a program to demonstrate sub-netting and find the sub-net masks.

  10:57 PM    Dnyaneshwar Kudande

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//Write a program in Python to demonstrate sub-netting and find the sub-net masks.

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))

#print "mask: ", mask

# Initialize net and binary and netmask with addr to get network
net = []
for i in range(4):
net.append(int(addr[i]) & mask[i])

#print "net : " , net

# 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 "broad: ", broad

# 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))


//Here is sample for try1.py

net = [200, 100, 33, 64]
broad = list(net)
brange = 32 - 23
for i in range(brange):
broad[3 - i/8] = broad[3 - i/8] + (1 << (i % 8))

print "broad: ", broad