Simple. How to devide 192.168.0.1 network on 3 equal subnets?

[webstd.design]

Simple question. How to devide 192.168.0.1 network on 3 equal subnets?

Just wondering what is your thinking

[Peter Paluch]

Hello,

Regardless of the original network address and mask, you can not divide a network into 3 equal subnets. Subnetting a network is done by "stealing" one or more bits from the former host part of the network, using them as a subnet ID, and subsequently shortening the host part to the remaining bits. If you steal 1 bit, you get 2 subnets. If you steal 2 bits, you get 4 (2*2) subnets. In general, if you steal N bits, you get 2**N subnets. Hence, the count of equal sized subnets can only be a power of two, i.e. 2, 4, 8, 16, 32, etc.

If you were allowed to create unequal sized subnets, it would be possible to get 3 subnets: divide the network into two halves, and divide one of the halves again, so for example:

192.168.1.0/24 -> 192.168.1.0/25, 192.168.1.128/26, 192.168.1.192/26

Best regards,

Peter

[Joseph W. Doherty · Accepted solution]

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Posting

Beyond what Peter has already correctly stated, you could divide one subnet into three equal sized subnets if we further note we're not going to use all the subnetted address space.

For example, if we divide any subnet into four equal sized subnets, you can then use any three of the four.

[webstd.design]

My question is how to find out the equal subnets, not just devide them.

For example if I want to devide network on 20 equal subnets for network 10.35.0.0

My example with 192.168.0.1 was not good, let's use 192.168.34.1 for instance

[Peter Paluch · Accepted solution]

Hello,

I am not quite sure if I understand you correctly. But as Joseph and I have tried to explain, it is not possible to create an arbitrary number of equally sized subnets from an original network. The number of equally sized subnets will always be only a power of two. It cannot be for example "20 equal subnets" as you requested - you can either create 16 or 32 equally sized subnets but nothing inbetween, so certainly not 20. Even if you do not use all of the created subnets as Joseph suggested, you have nonetheless created them and they do exist.

In addition, if you want to subnet a network, you must first know both its address and netmask. Your examples of "network addresses" lack the netmask information, and by themselves, they are not network addresses at all - neither 192.168.0.1 nor 192.168.34.1 can be a network address - it is a host address. A network address can be, for example, 192.168.0.0 or 192.168.34.0, if taking netmask of /24 or more.

Please give all of this a good thought and feel welcome to come back with any of your further questions.

Best regards,

Peter