Chapter 3: Introduction To TCP/IP

Question 1

Port 21

Answer 1

FTP

Question 2

Port 23

Answer 2

Telnet

Question 3

Port 110

Answer 3

POP3

Question 4

Port 53

Answer 4

DNS

Question 5

Port 69

Answer 5

TFTP

Question 6

Port 67

Answer 6

BootPS

Question 7

Port 80

Answer 7

HTTP

Question 8

Port 25

Answer 8

SMTP

Question 9

Port 20

Answer 9

FTP

Question 10

Port 443

Answer 10

HTTPS

Question 11

Port 22

Answer 11

SSH

Question 12

Port 123

Answer 12

NTP

Question 13

Port 143

Answer 13

IMAP4

Question 14

What makes TCP reliable?

Answer 14

Sequencing, acknowledgements, and flow control (windowing). UDP does not have reliability.

Question 15

In the DoD model, what are the two main reasons for the Internet layer’s existence?

Answer 15

Routing and providing a single network interface to the upper layers.

Question 16

Protocol 6

Answer 16

TCP

Question 17

Protocol 17

Answer 17

UDP

Question 18

What does ARP do?

Answer 18

ARP resolves IP addresses to Ethernet (MAC) addresses.

Question 19

What is RARP?

Answer 19

RARP resolves Ethernet (MAC) addresses to IP addresses.

Question 20

What is the Class A reserved / private address space?

Answer 20

10.0.0.0 through 10.255.255.255

Question 21

What is the Class B reserved / private address space?

Answer 21

172.16.0.0 through 172.31.255.255

Question 22

What is the Class C reserved / private address space?

Answer 22

192.168.0.0 through 192.168.255.255

Question 23

What is the IP range for a Class A network?

Answer 23

1-126

Question 24

What is the IP range for a Class B network?

Answer 24

128-191

Question 25

What is the IP range for a Class C network?

Answer 25

192-223

Question 26

What is the difference between a broadcast, unicast, and multicast address?

Answer 26

A broadcast is all devices in a subnet, a unicast is to one device, a multicast is to some but not all devices.

Question 27

What are the key features of TCP?

Answer 27

Sequenced, Reliable, Connection-Oriented, Virtual circuit, Acknowledgements, Windowing flow control

Question 27

What are the key features of UDP?

Answer 27

Unsequenced, Unreliable, Connectionless, Low overhead, No acknowledgement, No windowing or flow control of any type

Question 27

What are the key protocols that use TCP?

Answer 27

Telnet, SMTP, HTTP, FTP, DNS, HTTPS, SSH, POP3, NTP, IMAP4

Question 27

What are the key protocols that use UDP?

Answer 27

SNMP, TFTP, DNS, BootPS/DHCP

Question 28

What are the four layers of the DoD model?

Answer 28

Process/Application Host-to-Host Internet Network Access

Question 29

The Process/Application layer defines:

Answer 29

Node-to-node application communication and also controls user-interface specifications

Question 30

The DoD host-to-host layer parallels which OSI layer?

Answer 30

The Transport Layer

Question 31

The DoD Internet layer parallels which OSI layer?

Answer 31

The Network Layer

Question 32

The DoD Network layer parallels which OSI layer?

Answer 32

Data Link and Physical Layers

Question 33

What protocols reside in the Host-to-Host layer?

Answer 33

TCP/UDP

Question 34

Which protocols reside at the DoD Internet layer?

Answer 34

ICMP/ARP/RARP/IP

Question 35

Which protocols reside at the DoD Network Access layer?

Answer 35

Ethernet/Fast Ethernet/Token Ring/FDDI

Question 36

What is contained in the TCP header of a connection oriented transmission?

Answer 36

Source port. Destination port, sequence number, acknowledgement number, header length, future use field, window size, checksum, urgent pointer, options field, and finally data.

Question 37

What is contained in the UDP header of a connectionless transmission?

Answer 37

Source port, destination port, length, checksum and data.

Question 38

What is in the IP header?

Answer 38

Version, header length, priority or type of service, total length id, flags, fragment offset, time to live, protocol, header checksum, source IP address, dest address, options, data

Question 39

On which layer is ICMP?

Answer 39

Network

Question 40

What is the 127.0.0.1 address used for?

Answer 40

Loop back and testing