Computer & Networks Essentials - IP Address Assignment and Subnetting

This set covers IP address assignment and subnetting concepts, including default subnet masks, testing tools like Ping and TRACERT, and formulas for FLSM and VLSM calculations.

Subnet Mask

A value that differentiates the Network and Host portions of an IP address, represented with all 1’s in the network portion and all 0’s in the host portion.

Class A Default Subnet Mask

The default mask for Class A addresses, specified as $255.0.0.0$ (N.H.H.H).

Class B Default Subnet Mask

The default mask for Class B addresses, specified as $255.255.0.0$ (N.N.H.H).

Class C Default Subnet Mask

The default mask for Class C addresses, specified as $255.255.255.0$ (N.N.N.H).

AND Table Rule

The output is $1$ if both its inputs are $1$. For all other possible inputs, the output is $0$.

Ping

A command used to verify that a device can communicate with another on a network; for example, ping .

TRACERT (Trace Route)

A command-line utility used to trace the path that an Internet Protocol (IP) packet takes to its destination.

Subnetting

The process of dividing a single network into multiple smaller networks to help minimize the wastage of IP addresses.

FLSM

Fixed Length Subnet Mask.

VLSM

Variable Length Subnet Mask, which is the process of subnetting a subnet to include more than one subnet mask within a major network.

Requirement of Hosts Formula

Used to determine host bits required where $2^h - 2 \text{ is } \boldsymbol{\text{greater than or equal to}} \text{ requirement}$, where $h$ is the number of host bits.

Requirement of Networks Formula

Used to determine network bits required where $2^n \text{ is } \boldsymbol{\text{greater than or equal to}} \text{ requirement}$, where $n$ is the number of network bits.

The Increment

The value used to find network ranges (e.g., if $3$ bits are reserved in a Class C subnet mask, the increment is $32$).

$H$ (in Subnetting)

Represents the number of Host bits.

$N$ (in Subnetting)

Represents the number of Network bits.

Network ID and Broadcast ID exclusion

The process of subtracting $2$ from the total number of hosts ($2^h - 2$) to account for these two specific addresses.