# Midterm Sample Questions

Difference between NAS and SAN?

Subnet: 

* What kind of class is the given IP?

* What is the subnet mask, network address, etc?

* Subnet addresses?

`Host & subnet mask(classless)`

BTW: this is the analog of the network address(classful addressing). When we talk about network addresses we are implying a classful network.

* Subnet bits

i.e. 21 => 8+8+5+0 <= `5` is the odd one out so we have _5 subnet bits_

* VLSM - Variable Length Subnet Mask


Suppose we want to assign addresses to the following networks with x many hosts.
A:600; B:1000; C:200

`150.180.0.0/16`
`150.181.0.0/16`

Start with the largest network B : requires 1000 hosts.

Hosts part requires 10 bits so we have an IP/22.

Network address then is (subnet address)150.180.0.0/22 - (broadcast address)150.180.3.255/22

**NOTE:** I included both the subnet(network) address and the broadcast for sake of brevity.