subneting .. is 192.168.0.1/24 different than 192.168.0.1/25

Posted by SM on Server Fault See other posts from Server Fault or by SM
Published on 2010-04-19T06:26:48Z Indexed on 2010/04/19 6:34 UTC
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subnet

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subnetting

So i am trying to understand subnetting. I understand that you can take 192.168.0.0/24 domain and break it up in 2 subnets. 192.168.0.0/25 and 192.168.0.128/25 .. so what if i need to create 2 more subnets inside both of those above subnets.

What if i need to create 2 subnets, which have 2 more subnets inside them and each of those 2 subnets have 2 hosts. As per my calculation, this would be something like.

top 2 subnets: 192.168.0.0/25 and 192.168.0.128/25

subnets of 192.168.0.0/25: 192.168.0.0/26 - 192.168.0.128/26

subnets of 192.168.0.128/25: 192.168.0.128/26 - 192.168.0.192/26

hosts of 192.168.0.0/25: 192.168.0.1/25 - 192.168.0.2/25

hosts of 192.168.0.128/25: 192.168.0.129/25 - 192.168.0.130/25

hosts of 192.168.0.0/26: 192.168.0.1/26 - 192.168.0.2/26

hosts of 192.168.0.128/26: 192.168.0.129/26 - 192.168.0.130/26

hosts of 192.168.0.128/26: 192.168.0.129/26 - 192.168.0.130/26

hosts of 192.168.0.192/26: 192.168.0.193/26 - 192.168.0.194/26

The above doesnt seem right, i am moving down like a tree, however the subnet mask and IPs are being repeated, i am just add 1 to /x and making the ips from there. Can anyone please tell me if this is correct

The scenario i am trying to understand is similar to this, however i just want to add hosts on each level as well. http://www.ciscotrick.com/wp-content/uploads/2008/08/the_mathematical_relationship_between_network_block_sizes.jpg

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