lesson 5B Flashcards
What is Layer 2 in a network, and what does it do?
Layer 2 is the Data Link Layer. It uses MAC addresses to forward data within the same local area (subnet) using switches. It ensures that devices in the same subnet can communicate directly.
What is Layer 3 in a network, and what is its main function?
Layer 3 is the Network Layer. It uses IP addresses to route data between different subnets and across networks using routers. This layer allows devices in different subnets to communicate.
How do switches and routers differ in a network?
Switches operate at Layer 2 and use MAC addresses to forward data within a local area (subnet). Routers operate at Layer 3 and use IP addresses to route data between different subnets and networks
What is a MAC address, and why is it important?
A MAC address is a unique identifier for each device on a network, like a postal code for houses. It is used by switches at Layer 2 to forward data within the same subnet.
What is an IP address, and why do we need it?
An IP address is a unique address for each device on a network, similar to a full mailing address. It is used by routers at Layer 3 to route data between different subnets and networks
What happens if two devices are in the same subnet and want to communicate?
If two devices are in the same subnet, they use MAC addresses to communicate directly. The switch forwards data using these MAC addresses within the local area.
What is a default gateway, and when is it used?
A default gateway is a router that forwards data to other subnets when the destination IP address is different from the source subnet. It is used when devices need to communicate with devices in different subnets.
What is ARP, and what does it do?
ARP (Address Resolution Protocol) is used to match an IP address to a MAC address within the same subnet. It helps devices find the correct MAC address to send data to.
How does ARP work when two devices are in the same subnet?
The sending device sends an ARP request asking, “Who has this IP address?” The device with that IP address responds with its MAC address, allowing the sender to forward data correctly.
What happens if the destination IP address is not in the same subnet as the source?
If the destination IP is different, the source device sends the data to the default gateway (router). The router then forwards the data to the correct subnet or next router based on its routing table.
What is unicast addressing?
Unicast addressing is when a computer sends a message to one specific computer using its unique IP address. It’s like sending a letter to one friend.
What is broadcast addressing?
Broadcast addressing sends a message to all computers in a network. It’s like making an announcement that everyone in the school hears.
What is a broadcast address?
A broadcast address is the special address used to send a message to every computer in a network. It is the last address in the IP address range for that network.
How is the broadcast address determined?
To find the broadcast address, set all the host bits to 1 in the IP address. For example, with a subnet mask of 255.255.255.240, the last address is the broadcast address.
What is multicast addressing?
Multicast addressing sends a message to a group of computers that want to receive it. It’s like sending an invitation to all members of a club.
