Networking: Devices, Topologies & Protocols
🔒 Log in to trackNetwork types and topologies, devices (hub/switch/router), the OSI model, IP addressing and TCP/UDP with port numbers. Device-to-layer matching and IP-class identification are CKT regulars.
One page per subtopic: detailed notes, every question type, formulas, tricks and practice sets.
Every formula on one printable page, grouped by subtopic.
4 exam-level questions worked step by step.
83 questions — untimed practice or a timed test with analysis.
Track record in the exam
Test difficulty mix (83 questions)
Question patterns exams keep repeating
Taken from previous-year papers. If a pattern is marked "very common", expect to see it in your exam.
Name the network device
very common"Which device sends data to the correct network using IP addresses?"
Hub sends to all ports. Switch sends only to the right port.
Router joins different networks. Repeater boosts a weak signal.
Which device forwards data packets towards the correct network using IP addresses?
Hub and switch work inside one network
Joining networks needs IP addresses
That job belongs to a router
Answer: Router
OSI model layers
very common"Routing is a function of which OSI layer?" or "how many layers in OSI?"
OSI has 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, Application.
Routing and IP = Network layer.
In the OSI model, routing of packets is done by which layer?
Layer 3 handles IP addresses and routes
Layer 3 is called the Network layer
Transport (layer 4) only delivers end to end
Answer: Network layer
IP address class
very commonAn IP address like 130.10.5.2 is given and its class is asked.
Look only at the first number.
1-126 = A, 128-191 = B, 192-223 = C, 224-239 = D.
Which class does the IP address 130.10.5.2 belong to?
First number = 130
128 to 191 is Class B
130 is in that range
Answer: Class B
Port numbers
very common"HTTPS uses which port?" or "SMTP port number".
Learn: HTTP 80, HTTPS 443, FTP 21, SSH 22, Telnet 23, SMTP 25, DNS 53.
POP3 is 110, IMAP is 143.
Which default port does HTTPS use?
HTTP uses port 80
HTTPS is the secure version of HTTP
It has its own port
Answer: 443
TCP or UDP
very common"Which protocol is best for live streaming or file download?"
TCP = reliable and ordered (web pages, file download).
UDP = fast, no guarantee (live video, gaming).
Which protocol would a live video streaming service prefer?
Live video needs speed
A few lost packets do not matter
TCP would pause to resend them
Answer: UDP
Network topology
common"All computers are connected to a central hub" and the topology is asked.
Central device = Star. Every node linked to every other = Mesh.
One common cable = Bus. A circle = Ring.
All computers are connected to one central hub. Which topology is this?
One central device in the middle
Every computer has its own cable to it
The shape looks like a star
Answer: Star topology
Links in a mesh network
occasional"How many links are needed for a mesh of 6 computers?"
Use n × (n − 1) ÷ 2.
Do not forget to divide by 2.
How many cable links are needed for a full mesh of 6 computers?
n = 6
n × (n − 1) = 6 × 5 = 30
Divide by 2: 30 ÷ 2
= 15 links