Subnetting: Network with six subnets
I'm reading "Windows Networking Essential" and my question is about subnetting.
I understand that in order to create subnets, I need to borrow from the host bit of the address.
In the book, it says that
So if I I want to create four subnets, I borrow two bits, if I borrow three, I get eight subnets etc.
But how do I create, for example, six subnets?
For example, with the IP address 192.168.50.0 how is it possible to create six subnets?
To create four subnets, I borrow two bits:
11000000 10101000 00110010 00000000
What would you do to create six subnets?
Another important question is: If no network mask is given, can I assume that it's 255.255.255.0 ?
I understand that in order to create subnets, I need to borrow from the host bit of the address.
In the book, it says that
...you can use the following formula to determine how many subnets you can create based on how many bits you borrow: 2n, where n is the number of bits you borrow.
So if I I want to create four subnets, I borrow two bits, if I borrow three, I get eight subnets etc.
But how do I create, for example, six subnets?
For example, with the IP address 192.168.50.0 how is it possible to create six subnets?
To create four subnets, I borrow two bits:
11000000 10101000 00110010 00000000
What would you do to create six subnets?
Another important question is: If no network mask is given, can I assume that it's 255.255.255.0 ?
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Then the netmask changes from
11111111 11111111 11111111 00000000 to
11111111 11111111 11111111 11100000 = 255.255.255.224
When I apply it to the IP address (in order to determine the network ID)
IP Address: 11000000 10101000 00110010 00000000
Netmask: 11111111 11111111 11111111 11100000
ID: 11000000 10101000 00110010 00000000
I get 192.168.50.0 as the network ID. Is that correct?
11111111 11111111 11111111 00000000 to
11111111 11111111 11111111 11100000 = 255.255.255.224
When I apply it to the IP address (in order to determine the network ID)
IP Address: 11000000 10101000 00110010 00000000
Netmask: 11111111 11111111 11111111 11100000
ID: 11000000 10101000 00110010 00000000
I get 192.168.50.0 as the network ID. Is that correct?
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and the next one is 192.168.50.32, .64, .96 aso.
ASKER
For the sake of completeness (if following my book) .. so it looks right.
1 000 192.168.50.0 192.168.50.1 – 192.168.50.30
2 001 192.168.50.32 192.168.50.33 – 192.168.50.62
3 010 192.168.50.64 192.168.50.65 – 192.168.50.94
4 011 192.168.50.96 192.168.50.97 – 192.168.50.126
5 100 192.168.50.128 192.168.50.129 – 192.168.50.158
6 101 192.168.50.160 192.168.50.161 – 192.168.50.190
7 110 192.168.50.192 192.168.50.193 – 192.168.50.222
8 111 192.168.50.224 192.168.50.225 – 192.168.50.254
Bing, you wrote that ,
I assume this is something more advanced?
Is it like setting the default gateway of network 8 to the subnet of network 7 for example?
1 000 192.168.50.0 192.168.50.1 – 192.168.50.30
2 001 192.168.50.32 192.168.50.33 – 192.168.50.62
3 010 192.168.50.64 192.168.50.65 – 192.168.50.94
4 011 192.168.50.96 192.168.50.97 – 192.168.50.126
5 100 192.168.50.128 192.168.50.129 – 192.168.50.158
6 101 192.168.50.160 192.168.50.161 – 192.168.50.190
7 110 192.168.50.192 192.168.50.193 – 192.168.50.222
8 111 192.168.50.224 192.168.50.225 – 192.168.50.254
Bing, you wrote that ,
the unused subnets can be merged into two of existing eight subnets.
I assume this is something more advanced?
Is it like setting the default gateway of network 8 to the subnet of network 7 for example?
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Thanks a lot for your help!
this is for 4 same-size subnets, each has 32 IPs (30 workable IPs available).
>> with the IP address 192.168.50.0 how is it possible to create six subnets
you may simply "borrow" one more bit for 2 of the 4 above subnrts, then 6 subnrts will be available in the original class C space, 32 IPs for two subnets (mask 224), and 16 IPs for four subnets (mask 240).
> 6 subnets require 3 bits = 8 subnets. with two subnets unused.
leaving two unused subnets is not necessary, the unused subnets can be merged into two of existing eight subnets.