COMPTIA NETWORK+ (N10-009) EXAM 2026
REVISION QUESTIONS AND ANSWERS
◉ Describe layer 1 of the OSI model Answer: Physical layer --
signaling, cabling, connections
No protocols
◉ Examples of layer 1 issues and solutions Answer: Fix cabling,
punch-downs, etc.
Run loopback tests, test/replace cables, swap adapter cards
◉ Loopback test Answer: A diagnostic procedure that verifies the
integrity of a communication pathway by sending a signal from a
device and returning it to the same device
◉ Describe layer 2 of the OSI model Answer: Data Link layer, the
basic network "language", the foundation of communication
* MAC address on Ethernet
The "switching" layer
◉ Describe layer 3 of the OSI model Answer: Network layer, the
"routing layer"
* Internet Protocol (IP)
,* Fragments frames to traverse different networks
◉ Describe layer 4 of the OSI model Answer: Transport layer, the
"post office" layer, parcels and lettings from one side of the network
to the other
* TCP & UDP
◉ Describe layer 5 of the OSI model Answer: Session layer,
communication between devices (start, stop, restart)
* Control protocols, tunneling protocols
◉ Describe layer 6 of the OSI model Answer: Presentation layer
* Character encoding
* Application encryption
* Often combined with layer 7, the application layer
◉ Describe layer 7 of the OSI model Answer: Application layer, the
layer we see
* HTTP, FTP, DNS, POP3
◉ OSI model mapped to real-world Answer: Layer 7 = Your eyes
Layer 6 = Application encryption (SSL/TLS)
Layer 5 = Control protocols, tunneling protocols
,Layer 4 = TCP segment, UDP datagram
Layer 3 = IP Address, Router, Packet
Layer 2 = Frame, MAC address, Extended Unique Identifier (EUI-48,
EUI-64), Switch
Layer 1 = Cables, fiber, and the signal itself
◉ Real-world example of the OSI model Answer: Application:
https://mail.google.com
Presentation: SSL encryption
Session: Link the presentation to the transport
Transport: TCP encapsulation
Network: IP encapsulation
Data Link: Ethernet
Physical: Electrical signals
◉ Router Answer: - Routes traffic between IP subnets
- OSI layer 3 devices
- Routers inside of switches sometimes called "layer 3 switches"
- Often connects diverse network types
* LAN, WAN, copper, fiber
◉ Switch Answer: - Forwards traffic based on data link address
, - May provide PoE (Power over Ethernet)
◉ Multilayer switch Answer: includes layer 3 (routing) functionality
◉ Application-specific integrated circuit (ASIC) Answer: Type of
processor designed to perform a specific function, such as switching.
◉ Firewall Answer: - Filters traffic by port number or application
- Encrypts traffic, VPN between sites
- Most firewalls can be layer 3 devices (routers)
* Network Address Translation (NAT)
* Dynamic routing
◉ Where does a firewall sit on the network? Answer: Often in the
ingress/egress
◉ What is the difference between a traditional firewall and NGFW?
(new generation firewall) Answer: A NGFW can manage applications
◉ What is the difference between an IDS (Intrusion Detection
System) and an IPS (Intrusion Prevention system)? Answer: An IDS
is worse because it can only detect and alert for traffic while IPS can
alert and stop the malicious traffic
REVISION QUESTIONS AND ANSWERS
◉ Describe layer 1 of the OSI model Answer: Physical layer --
signaling, cabling, connections
No protocols
◉ Examples of layer 1 issues and solutions Answer: Fix cabling,
punch-downs, etc.
Run loopback tests, test/replace cables, swap adapter cards
◉ Loopback test Answer: A diagnostic procedure that verifies the
integrity of a communication pathway by sending a signal from a
device and returning it to the same device
◉ Describe layer 2 of the OSI model Answer: Data Link layer, the
basic network "language", the foundation of communication
* MAC address on Ethernet
The "switching" layer
◉ Describe layer 3 of the OSI model Answer: Network layer, the
"routing layer"
* Internet Protocol (IP)
,* Fragments frames to traverse different networks
◉ Describe layer 4 of the OSI model Answer: Transport layer, the
"post office" layer, parcels and lettings from one side of the network
to the other
* TCP & UDP
◉ Describe layer 5 of the OSI model Answer: Session layer,
communication between devices (start, stop, restart)
* Control protocols, tunneling protocols
◉ Describe layer 6 of the OSI model Answer: Presentation layer
* Character encoding
* Application encryption
* Often combined with layer 7, the application layer
◉ Describe layer 7 of the OSI model Answer: Application layer, the
layer we see
* HTTP, FTP, DNS, POP3
◉ OSI model mapped to real-world Answer: Layer 7 = Your eyes
Layer 6 = Application encryption (SSL/TLS)
Layer 5 = Control protocols, tunneling protocols
,Layer 4 = TCP segment, UDP datagram
Layer 3 = IP Address, Router, Packet
Layer 2 = Frame, MAC address, Extended Unique Identifier (EUI-48,
EUI-64), Switch
Layer 1 = Cables, fiber, and the signal itself
◉ Real-world example of the OSI model Answer: Application:
https://mail.google.com
Presentation: SSL encryption
Session: Link the presentation to the transport
Transport: TCP encapsulation
Network: IP encapsulation
Data Link: Ethernet
Physical: Electrical signals
◉ Router Answer: - Routes traffic between IP subnets
- OSI layer 3 devices
- Routers inside of switches sometimes called "layer 3 switches"
- Often connects diverse network types
* LAN, WAN, copper, fiber
◉ Switch Answer: - Forwards traffic based on data link address
, - May provide PoE (Power over Ethernet)
◉ Multilayer switch Answer: includes layer 3 (routing) functionality
◉ Application-specific integrated circuit (ASIC) Answer: Type of
processor designed to perform a specific function, such as switching.
◉ Firewall Answer: - Filters traffic by port number or application
- Encrypts traffic, VPN between sites
- Most firewalls can be layer 3 devices (routers)
* Network Address Translation (NAT)
* Dynamic routing
◉ Where does a firewall sit on the network? Answer: Often in the
ingress/egress
◉ What is the difference between a traditional firewall and NGFW?
(new generation firewall) Answer: A NGFW can manage applications
◉ What is the difference between an IDS (Intrusion Detection
System) and an IPS (Intrusion Prevention system)? Answer: An IDS
is worse because it can only detect and alert for traffic while IPS can
alert and stop the malicious traffic
