Return to course: Networking 102: The OSI Model
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Course Overview
End Of Course Quiz
What does OSI stand for?
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Open Source Infrastructure
Open Systems Interconnection
Operational Signal Interface
Output System Integration
How many layers are in the OSI model?
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4
5
7
10
Which mnemonic helps remember the OSI layers from Layer 1 to Layer 7?
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"All People Seem To Need Data Processing"
"Please Do Not Throw Sausage Pizza Away"
"People Don't Need Those Stupid Packets Anyway"
"Always Start Physical, Then Data Networking"
Which OSI layer deals with cables, connectors, and electrical signals?
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Layer 1 – Physical
Layer 2 – Data Link
Layer 3 – Network
Layer 4 – Transport
According to the course, approximately what percentage of network problems are Layer 1 issues?
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20%
50%
80%
95%
What type of address operates at Layer 2?
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IP address
MAC address
Port number
DNS name
What is the primary device that operates at Layer 2?
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Router
Hub
Switch
Firewall
How does a switch know which port to forward a frame to?
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It checks the IP address against a routing table
It sends the frame to all ports
It uses DNS to look up the destination
It checks the MAC address against its MAC address table
What type of address operates at Layer 3?
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MAC Address
Port Number
Session ID
IP Address
What is the primary device that operates at Layer 3?
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Router
Hub
Access Point
Switch
When a device needs to send data to a different network (different subnet), what does it do?
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Sends directly using the destination MAC address
Broadcasts to all devices
Sends to its default gateway
Drops the packet
Which two protocols operate at Layer 4?
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TCP and UDP
HTTP and HTTPS
IP and ICMP
Ethernet and Wi-Fi
Why does Dante audio use UDP instead of TCP?
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UDP is more secure
UDP guarantees packet delivery
UDP prioritizes speed over reliability
TCP doesn't work over Ethernet
What do port numbers identify at Layer 4?
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Physical switch ports
Which application should receive the data
Which VLAN the device belongs to
The device's MAC address
Which OSI layers are combined into the "Application" layer in the TCP/IP model?
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Layers 1 and 2
Layers 3 and 4
Layers 5, 6, and 7
Layers 4, 5 and 6
When troubleshooting a network issue, what is the recommended approach from the course?
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Start at Layer 7 and work down
Start at Layer 1 and work up
Only check Layer 3
Replace all cables first
A Dante device is connected but doesn't appear in Dante Controller. You verify the cable is plugged in and the link light is on. What layer should you check next?
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Layer 4 – Check if the correct ports are open
Layer 3 – Check if the IP address is valid
Layer 7 – Restart Dante Controller
Layer 2 – Check if the device is on the correct VLAN
For production troubleshooting, which layers does the course recommend focusing on?
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Layers 1-4
Layers 5-7
Only Layer 3
All 7 Layers equally
What is the broadcast MAC address that sends traffic to all devices in a VLAN?
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00:00:00:00:00:00
FF:FF:FF:FF:FF:FF
192.168.1.255
255.255.255.0
How does the course frame the relationship between OSI and TCP/IP models?
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OSI is outdated and should be replaced by TCP/IP
TCP/IP is theoretical while OSI is practical
OSI terminology is commonly used for troubleshooting
They are completely unrelated models
