ccna - subnetting

  noddy2121 09:05 01 Nov 2005


I am currently studying for ccna 2. I am doing a lot of subnetting practice, and there is always one thing that keeps slipping my mind.

Look at this network address below

In the second octet it is a zero, can zeros be used or not? or does my first range of subnets have to be one instead? like below

any help please



  mgmcc 12:37 01 Nov 2005

Yes zeros can be used. The most commonly used LAN subnet is 192.168.0.x with a mask of which gives addresses from to, so that contains a zero octet.

Change the mask to and you have a subnet from to

At one time I ran my LAN with all addresses in the 10.0.0.x range and subnet mask so, theoretically the subnet's address range was to

  Gaz 25 12:46 01 Nov 2005

My IP addressing at home is - for network one.

For my other network, which is seperated by routers. It is - (only need a few addresses, and it's redirected, VLANed and NAT'ed from the main network for security.


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