Reminder: The network portion of an IP address is the result of the bitwise & $($AND$)$ operation

on the IP address and subnet mask $($or netmask$).$ Remember the netmask may be written in

dotted decimal $($e$.$g$.255\mathrm{.}255\mathrm{.}240\mathrm{.}0)$ or it may be abbreviated using CIDR notation $($e$.$g$./20)$

EXAMPLE: Find the network portion of IP address $192\mathrm{.}168\mathrm{.}177\mathrm{.}134$ with subnet mask

$255\mathrm{.}255\mathrm{.}255\mathrm{.}192$

STEP $1$: Convert IP address to binary:$11000000101010001011000110000100$

STEP $2$: Convert netmask to binary: $11111111111111111111111111000000$

STEP $3$: calculate bitwise &: $11000000101010001010000110000000$

STEP $4$: Convert result to decimal: $192.168.177.128$

Result: $192\mathrm{.}168\mathrm{.}177\mathrm{.}128$

$1)$ Find the network portion of IP address $29\mathrm{.}172\mathrm{.}43\mathrm{.}79$ with netmask $255\mathrm{.}255\mathrm{.}248\mathrm{.}0$

STEP $1$:

STEP $2$:

STEP $3$:

STEP $4$:

Result:

$2)$ Find the network portion of IP address $201\mathrm{.}231\mathrm{.}164\mathrm{.}80$ with netmask $255\mathrm{.}255\mathrm{.}255\mathrm{.}192$

STEP $1$:

STEP $2$:

STEP $3$:

STEP $4$:

Result:

$3)$ Find the network portion of IP address $11\mathrm{.}147\mathrm{.}36\mathrm{.}94$ with netmask $255\mathrm{.}128\mathrm{.}0\mathrm{.}0$

STEP $1$:

STEP $2$:

STEP $3$:

STEP $4$:

Result:

$2022$ by Howard Community College. $2$

$4)$ Find the network portion of IP address $159\mathrm{.}124\mathrm{.}127\mathrm{.}32$ with netmask $/22$

STEP $1$:

STEP $2$:

STEP $3$:

STEP $4$:

Result:

$5)$ Find the network portion of IP address $129\mathrm{.}154\mathrm{.}127\mathrm{.}32$ with netmask $/27$

STEP $1$:

STEP $2$:

STEP $3$:

STEP $4$:

Result:

BONUS $(5$ points$)$: The IP address $223\mathrm{.}254\mathrm{.}27\mathrm{.}32$ is part of a Class C network. Find the network

portion of this IP address using the default netmask for a Class C network.

STEP $0$: the default netmask for a Class C Network:

STEP $1$:

STEP $2$:

STEP $3$:

STEP $4$:

Result: