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New Member

subnetting

If I was going to break down a class C using a subnet mask of 255.255.255.224 would I lose the first and last subnet? A lot of what I have read says a I would, but is that completely true or is there a work around?

  • Other Network Infrastructure Subjects
3 REPLIES
New Member

Re: subnetting

The first (all 0's subnet) and last (all 1's subnet) are both technically lost. However, "ip subnet-zero" allows you to use the first, and I believe that Cisco supports use of the all 1's.

The problem is that if you choose to use these subnets and you use devices that don't allow for both/either, you will face real connectivity issues.

Mick.

New Member

Re: subnetting

On a class C address with a mask of 224, you can have 8 subnets and 30 hosts per subnet.

Regards...Ketan Chaudhari, CCSA, CCNP, MCSE

New Member

Re: subnetting

All O's indicate the 'network portion", all I's indicate the broadcast. So unless you use subnet O yes you will not be able to use these subnets.

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