I'm confused with this, I have a class A ip address which is 10.0.0.0 /8 that would require 2000 subnets, 2n^11 = 2048.. so my network prefix would be /19 and subnet mask would be 255.255.224.0.
My question is this, If given the question "What is the usable address range of first subnet?" What could be my first subnet?
10.0.0.0 or 10.0.32.0 ?
Sorry for my english. Cheers!
To be honest, the strict convention of Class A, B or C isn't really used anymore. Just focus on your needs and what you have.
Address: 10.0.0.0/8
Subnets: 2000
To get 2000 subnets, your steps were right, you need 2^11 = 2048 available subnets. This gives you 10.0.0.0/19 as the first subnet. Now we can break this part further down. We have 13 host bits, leaving us with 2^13-2 = 8190 usable hosts.
1st Subnet: 10.0.0.0 /19
Network: 10.0.0.0
First Usable: 10.0.0.1
Last Usable: 10.0.31.254
Broadcast: 10.0.31.255
2nd Subnet: 10.0.32.0 /19
Network: 10.0.32.0
First Usable: 10.0.32.1
Last Usable: 10.0.63.254
Broadcast: 10.0.63.255