Vol 1 Part 1: Intro to Networking

Question 1

Which of the following are layer 4 protocols?
A. Ethernet
B. HTTP
C. TCP
D. IP

Answer 1

C. TCP

Question 2

What are the 5 layers of the TCP/IP Model?

Answer 2

Layer 1: Physical
Layer 2: Data link
Layer 3: Network (Also called Internet)
Layer 4: Transport
Layer 5: Application

Question 3

What are the names of the units at each layer in the TCP/IP Model?

Answer 3

Layer 1: Bits
Layer 2: Frames
Layer 3: Packets
Layer 4: Segments
Layer 5: Data

Question 4

What protocol operates at layer 1 and layer 2?

Answer 4

Ethernet (802.3) and Wi-Fi (802.11)

Question 5

What protocol operates at layer 3?

Answer 5

IP and ICMP

Question 6

What protocol operates at layer 4?

Answer 6

TCP/UDP

Question 7

What protocol operates at layer 5?

Answer 7

HTTP

Question 8

Error recovery operates at what layer?

Answer 8

Layer 3, network layer

Question 9

Error detection operates at what layer?

Answer 9

Layer 2, data link layer

Question 10

With TCP, what is used to conduct error recovery?

Answer 10

Sequences (SEQ) and Acknowledgements (ACK)

Question 11

With HTTP, what message does the client send to the server, and what message does the server then send back to the client?

Answer 11

GET followed by OK

Question 12

What is utilized from the frame to conduct error detection?

Answer 12

The Frame Check Sequence (FCS)

Question 13

What are the three components of the frame?

Answer 13

header, data, trailer

Question 14

The process of HTTP asking TCP to send some data and making sure it is received correctly is referred to as what kind of interaction?

Answer 14

Adjacent layer interaction

Question 15

The process of a web server adding a TCP header to the contents of a web page, followed by ading an IP header, and then adding a data-link header and trailer, is an example of what?

Answer 15

Data encapsulation

Question 16

Ethernet cables are twisted in order to reduce what?

Answer 16

Electromagnetic interference and crosstalk on the cable.

Question 17

A straight through cable utilizes what pins?

Answer 17

1, 2, 3, and 6

Question 18

What pins are flipped on a cross over cable?

Answer 18

white-orange with white-green, and orange with green

Question 19

A straight through cable is used when connecting what type of devices?

Answer 19

Dissimilar devices (computer to a hub or a switch)

Question 20

A crossover cable is used when connecting what type of devices?

Answer 20

Similar (switch to switch, computer to computer)

Question 21

1000BASE-LX is what kind of cable, and how do you know?

Answer 21

Fiber. The X indicates it is a fiber cable.

Question 22

What is the difference between multimode and singlemode fiber?

Answer 22

Multimode is faster but travels a smaller distance (500m), singlemode is slower but can travel a much further distance (40km)

Question 23

What is the minimum and maximum allowed size of data within a frame?

Answer 23

46 bytes and 1500 byes

Question 24

A frame larger than 1518 bytes but smaller than 1600 bytes is known as a what?

Answer 24

Baby giant

Question 25

What does the type refer to within a frame?

Answer 25

IPv4 vs IPv6

Question 26

Where in the frame is the FCS located?

Answer 26

The trailer

Question 27

How many bits are in a MAC address, what kind of characters are used, and explain the different parts of the address?

Answer 27

48bits/6bytes. 12 characters in Hexadecimal. The first 24 bits are the Organizational Unique Identifier (OUI) and reveal who made the device. The last 24 bits are vendor assigned.

Question 28

What is the difference between full duplex and half duplex?

Answer 28

Full duplex allows a device to send and receive at the same time. Half duplex limits the device to doing one at a time.

Question 29

What type of leased line transmits data at 1.544 megabits per second?

Answer 29

T1

Question 30

What are the two types of serial WAN link proocols, and who uses them?

Answer 30

HLDC and PPP. HLDC is Cisco proprietary while PPP is vendor neutral and used more often than HLDC.

Question 31

Routers act as the what for host devices? Hint, it is known as the default router...

Answer 31

Gateway

Question 32

What dos the Domain Name System (DNS) do?

Answer 32

Resolves names into IP addresses (ie. www.google.com into 8.8.8.8)

Question 33

What does the Address Resolution Protocol (ARP) do?

Answer 33

Resolves IP addresses into MAC addresses.

Question 34

At what layer does the Ping and ICMP Echo operate at?

Answer 34

Layer 3

Question 35

What kind of connector is used for modern networks to allow different ethernet connectors such as fiber?

Answer 35

SFP+

Question 36

What part of the fiber cable is responsible for reflecting the light source?

Answer 36

Cladding

Question 37

A hub operates at layer 1 and transmits data in what duplex mode?

Answer 37

Half duplex

Question 38

True or False: Routers must be configured to learn every possible route, including its own connections?

Answer 38

FALSE

Question 39

What happens to a packet when a host attempts to send a packet to a destination IP address is located in a different subnet?

Answer 39

The packet is sent to the default gateway where the router then sends the packet to the appropriate subnet using its routing table.

Question 40

How does ARP work?

Answer 40

The router sends a broadcast to all devices on the subnet to find the MAC address. If the MAC address is found, then the switch sends an ARP reply to the router stating the original IP address and the matching MAC. This information is then stored in the ARP table.

Question 41

What field do Cisco routers add into the HDLC header?

Answer 41

Type

Question 42

Which protocol requires a PC to learn information from some other server device?

Answer 42

DNS