# IP address ending by 0 = IP Network Address?

IP address ending by 0 = IP Network Address?

## Myth

IP address ending by 0 = IP Network Address?

It is a popular belief that all IP addresses ending with 0 being the network address.

## Reality

False: I will not go into detail on how to identify a network address or host address. But here's an example of IP type xxx0 that will perfectly fit for a host:

If I take the example of the network 10.0.0.0/23 or 255.255.254.0 in this case certainly is a 10.0.0.0 network address but not 10.0.1.0.

## Explanations

10.0.0.0 in binary becomes
0000 1010.0000 0000 .0000 0000.0000 0000

and 255.255.254.0 in binary becomes
1111 1111.1111 1111 .1111 1110.0000 0000

So the valid host IP addresses are:
0000 1010.0000 0000.0000 0000.0000 0001 à 0000 1010.0000 0000.0000 0001.1111 1110
or

10.0.0.1 à 10.0.1.254 (10.0.1.255 then the broadcast address)

Then the next host IP address is valid:
0000 1010.0000 0000.0000 0001.0000 0000
or
10.0.1.0

Thanks to Nitch for this tip
Published by jak58. Latest update on April 1, 2010 at 09:33 AM by jak58.