At which layer of the OSI model do ethernet switches operate?
Layer two (Data Link Layer)
Ethernet switches make forwarding decisions based on layer information from the ethernet header of the ethernet frame.
What type of table do ethernet switches use to make forwarding decisions?
MAC address table
The MAC address table is used to store the MAC addresses of connected devices.
True or false: Ethernet switches forward frames based on the destination MAC address.
TRUE
The switch looks up the destination MAC address in its MAC address table to determine the correct port for forwarding.
What does an ethernet frame contain that is crucial for switches to make forwarding decisions?
Source and destination MAC addresses
The source MAC address identifies the sender, while the destination MAC address indicates the intended recipient.
In the example, what is the abbreviated MAC address for host one?
AAAA
This address represents the MAC address of host one in the example provided.
How does the switch determine where to forward the frame destined for H4?
By looking up the destination MAC address (DDDD) in its MAC address table
The switch forwards the frame out of the port associated with the destination MAC address.
What is the port number used by the switch to forward the frame to the destination MAC address DDDD?
Fast Ethernet 04
This port is where the destination device is connected, as indicated in the MAC address table.
What is the purpose of a MAC address table in a switch?
To store the source MAC addresses and their corresponding incoming ports
The MAC address table helps the switch make forwarding decisions based on layer two information.
When a switch receives an ethernet frame, what is the first action it takes?
It examines the source MAC address to check if it has learned anything new
If the source MAC address is not in the table, it adds it along with the incoming port.
What happens if the destination MAC address is not found in the switch’s MAC address table?
The switch performs an unknown unicast, sending the frame out of all ports except the incoming port
This behavior is similar to that of older ethernet hubs.
What does a device do when it receives an ethernet frame but its MAC address does not match the destination MAC address?
It ignores the rest of the frame
Only the device with the matching MAC address processes the frame.
In the scenario described, what does the switch do when it receives a frame from H4 with a source MAC address that is not in its table?
It adds the source MAC address to the MAC address table and notes the incoming port
This allows the switch to learn the location of devices on the network.
How long does a switch typically keep information about learned MAC addresses in its table?
For about five minutes
This time limit helps manage the table size and ensures it reflects current network conditions.
When forwarding a frame, what does the switch do if it already knows the destination MAC address?
It sends the frame out only through the specific port associated with that MAC address
This improves efficiency by reducing unnecessary traffic on the network.
Fill in the blank: The switch acts like an old ethernet hub when it encounters an unknown unicast by sending the frame out of _______.
all ports except the incoming port
This ensures that the frame reaches the intended recipient, even if the switch does not know its location.
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Module 1: Network Types35
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Module 1: Data Transmission41
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Module 1: Bandwidth & Throughput19
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Module 2: Client & Servers45
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Module 2: Network Components37
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Module 2: ISP Connectivity Options55
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Module 3: Wireless Networks And Mobile Device Connectivity102
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Module 4: Home Network Basics & Network Technologies In The Home45
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Module 4: Wireless Standards & Setting Up A Home Router72
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Module 5: Communication Protocols23
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Module 5: Communication Standards16
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Module 5: Network Communication Models45
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Module 6: Network Media Types28
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Module 7: Encapsulation And The Ethernet Frame19
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Module 7: The Access Layer15
