Network Functions and Equipment

Question 1

Collision Domain

Answer 1

• Every port on a Switch has it’s own Collision Domain

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Question 2

What is the primary function of a switch?

Answer 2

• receives data packets (frames) and directs them to their destination
• Connects devices to switch via cables
• learns MAC address and stores in CAM table
• Switch decides whether to forward or flood the packet (frame)

Question 3

How does a switch learn each connected device?

Answer 3

• as soon as a device sends a message into a switch, it learns their MAC address
• the MAC address is stored in the CAM table

Question 4

What is a CAM table?

Answer 4

• Content Addressible Memory

- Table of MAC addresses that has been learned by a switch

Question 5

When is a Frame forwarded vs. flooded by a Switch?

Answer 5

• A Frame is forwarded by a Switch when the Switch knows where the Frame is going (destination MAC address)
• A Frame is flooded by a Switch when the Switch does not know where the Frame is going (destination MAC address)

Question 6

What are the pieces of a Frame?

Answer 6

• FCS
• Data
• TCP/UDP Ports
• SRC IP
• DST IP
• SRC MAC
• DST MAC

Question 7

What is a Channel?

Answer 7

• a slice of the wifi radio frequency

Question 8

What happens as more devices join a Wifi frequency, such as 2.4?

Answer 8

• it degrades the quality of the connection since it is splitting up the bandwidth
• Devices need to take turns transmitting data

Question 9

What is the latest WIFI standard?

Answer 9

• 802.11 ax

- aka Wifi 6

Question 10

What does a Router do?

Answer 10

• connects networks
• determines if traffic should stay on the local network, or go to a remote network
• Controls brodcast and forward directed data packets between networks
• relies on IP-based routing table
• acts as a gateway between network types

Question 11

DNS Lookup

Answer 11

• computer tries to determine the IP address of a URL

Question 12

A computer would like to communicate with a server on the Internet. When it sends the communication request out of its network card, which destination MAC address would you expect to see in the header?

Answer 12

• The MAC address of the Router

Question 13

Typically, most of the core network equipment for an office are stored in a secured and delightfully cooled location known as the _____ ?

Answer 13

• MDF

- Main Distribution Facility

Question 14

All cables in an office usually run through the ceiling to a _____ before connecting to the switches

Answer 14

Patch Panel

Question 15

IDF

Answer 15

• Intermediate distribution facility

Question 16

An IDF doesn’t typically have a _____ installed in the rack. Why?

Answer 16

• Router

- the IDF feeds to the MDF, where the router is located

Question 17

Why do you have redundant connections between switches?

Answer 17

• Failover if one goes down

- LAG (etherchannel): combines the bandwidth of both connections into one; prevents a bottleneck