Network how many subnet?


1) This is related to network
- this has 32 block ip address
- 0 32 64 96 ....
- The first subnet: 192.168.1.(1-30)
- The 2nd subnet: 192.168.1.(33-62)
- So the hosts in every subnet is 30 from 2^5 - 2

2) My questions:i) How many SUBNETS does this network have?, ii) What is the FORMULA to calculate those subnets? ( I remember there is a formula for it but forget now; for example if we want to know how many "hosts" in every subnet; the formula for it is 2^5 - 2 = 30 hosts)

3) Any help for the two questions  above?
4) Thank you

Who is Participating?
ccie22921Connect With a Mentor Commented:
Okay, so what if the user is taking a test and does not have access to a subnet calc?  

Grenu, the formula is not the same.  WHen you are calculating usable hosts you subtract 2 so that you can define network and broadcast.  There is no need to do this when calculating the number of subnets.  

tjie what you need to know is that the formula to calculate usable host address is 2^3-2 and to calculate the number of subnets is 2^3 only.  In this case you would have eight subnets.  Which you do:  Look below please is your network is your usable host range is your broadcast address is your network -62 is your host range is your broadcast is your network 192.168.65 - 94 is your host range is your broadcast network 192.168.97-126 hosts broadcast network 192.168.129-158 hosts broadcast network 192.168.161-190 hosts broadcast network 192.168.193-222 hosts broadcast network 192.168.225-254 hosts broadcast

Viola, there are your eight subnets.

memo_tntConnect With a Mentor Commented:

hosts range: - per subnet

anyways :: use this link useful for subnets and wildcard calculations

Best Regards
GrenuConnect With a Mentor Commented:
The formula to calculate number of the subnets is the same 2^n-2, where n is the number of borrowed bits.
iI assume that the super network was and it was divided into a subnets with prefix on 27 bits. So in this case You have borowed 3 bits - You have 6 new networks (2^3-2=6), that You cen use without any problems.
The first one can be used however You have to remember that this is the subnet zero, co not all devicec can support it, You have to remember, this is why normalny you are not counging this subnet, the last subnet is "broadcast" subnet, sp You can not use it. The "broadcast" subnet is the one which have the same broadkasct address as the super network, which is divided into subnets.
Don JohnstonConnect With a Mentor InstructorCommented:
>How many SUBNETS does this network have?


>What is the FORMULA to calculate those subnets?

The same as used to calculate the number of hosts. Just don't subtract 2.

bits    subnets
1        2
2        4
3        8
4       16
5       32
6       64
7      128
8      256

and so on
well put Don
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