Subnetting question

Mystical_Ice
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Got a question, if someone can explain it to me -i took my CCNA, but like 7 years ago, and i forgot a lot of the theory.

If i have the network: 132.45.0.0 /18

1) What is the subnet? (this is the only one i could get - 255.255.192.0)
2) What is the bit mask?
3) I need to establish 8 subnets
3a) How many binary digits are required to define 8 subnets
3b) What is the subnet mask for the 8 subnets
3c) what would the IPs be for all 8 subnets
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VMware and Virtualization Consultant
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Commented:
1. 255.255.192.0
2. 11111111 11111111 11111111 11000000  
3. You'll only get 4, with a mask bit of 18.

b. Subnet Addresses

132.45.0.0
132.45.64.0
132.45.128.0
132.45.192.0

c. IP address

132.45.0.1 - 132.45.63.254
132.45.64.1 - 132.45.127.254
132.45.128.1 - 132.45.191.254
132.45.192.1 - 132.45.255.254

If you want 8 subnets, you would need to move to a subnet mask of 255.255.224 or /19 (mask bits)
or 11111111 11111111 11111111 11100000
Ernie BeekSenior infrastructure engineer
Top Expert 2012

Commented:
Can't beat hanccocka with this :)

But have a look at: http://www.subnet-calculator.com/cidr.php 
It's a nice tool which can help you out (myself as well when I'm lazy ;)

Author

Commented:
"If you want 8 subnets, you would need to move to a subnet mask of 255.255.224 or /19 (mask bits)", is that because it's a certain class subnet?

I remember the "n-2" number of subnets and "n-2" number of hosts, but you need to know what class it is first to do that right?
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Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
it's the mask bit, you need to apply a mask bit of /19 (255.255.224.0) to divide up the network range into 8 subnets.
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
you can use this class of network, just use a subnet mask of /19.

Author

Commented:
But as far as how many bits are for the host and how many bits are for the network, don't you need to know how many bits are 'borrowed' first?  Like in the example i posted that you helped me with, don't you need to know it's borrowing 2 bits from network and leaving 14 (8+6) for host?

my question is how do you know it's borrowing 2 bits - don't you need to know the class of network to be able to tell?
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
what are you tryimg to resolve?
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
thats another question?

one question per question.
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017

Commented:
Please post a new question, and link to this question as an example or relatef question.

Author

Commented:
Will do; thanks :)

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