Chapter 2: Tcp/ip Introduction

Front 1

What is the Class C address range in decimal and in binary?

Back 1

192–223, 110xxxxx

Front 2

What layer of the DoD model is equivalent to the Transport layer of the OSI model?

Back 2

Host-to-Host

Front 3

What is the valid range of a Class A network address?

Back 3

1–126

Front 4

What is the 127.0.0.1 address used for?

Back 4

Loopback or diagnostics

Front 5

How do you find the network address from a listed IP address?

Back 5

Turn all host bits off.

Front 6

How do you find the broadcast address from a listed IP address?

Back 6

Turn all host bits on.

Front 7

What is the Class B private IP address space?

Back 7

10.0.0.0 through 10.255.255.255

Front 8

What is the Class C private IP address space?

Back 8

172.16.0.0 through 172.31.255.255

Front 9

What are all the available characters that you can use in hexadecimal addressing?

Back 9

192.168.0.0 through 192.168.255.255

Front 10

What are all the available characters that you can use in hexadecimal addressing?

Back 10

0–9 and A, B, C, D, E, and F

Front 11

What are the decimal and hexadecimal equivalents of the binary number 10011101?
(Choose two.)
A. 159
B. 157
C. 185
D. 0x9D
E. 0xD9
F. 0x159

Back 11

B, D. To turn a binary number into decimal, you just have to add the values of each bit that
is a 1. The values of 10011101 are 128, 16, 8, 4, and 1. 128 + 16 + 8 + 4 + 1 = 157. Hexadecimal
is a base-16 number system. The values of hexadecimal are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A,
B, C, D, E, F—16 characters total, from which to create all the numbers you’ll ever need. So,
if 1001 in binary is 9, then the hexadecimal equivalent is 9. Since we then have 1101, which
is 13 in binary, the hexadecimal answer is D and the complete hexadecimal answer is 0x9D.
Even though binary/hex numbers were discussed in Chapter 1, a good review is necessary here.

Front 12

Which of the following allows a router to respond to an ARP request that is intended for a
remote host?
A. Gateway DP
B. Reverse ARP (RARP)
C. Proxy ARP
D. Inverse ARP (IARP)
E. Address Resolution Protocol (ARP)

Back 12

C. Proxy ARP can help machines on a subnet reach remote subnets without configuring routing
or a default gateway.

Front 13

You want to implement a mechanism that automates the IP configuration, including IP
address, subnet mask, default gateway, and DNS information. Which protocol will you use
to accomplish this?
A. SMTP
B. SNMP
C. DHCP
D. ARP

Back 13

C. Dynamic Host Configuration Protocol (DHCP) is used to provide IP information to hosts
on your network. DHCP can provide a lot of information, but the most common is IP address,
subnet mask, default gateway, and DNS information.

Front 14

What protocol is used to find the hardware address of a local device?
A. RARP
B. ARP
C. IP
D. ICMP
E. BootP

Back 14

B. Address Resolution Protocol (ARP) is used to find the hardware address from a known
IP address.

Front 15

Which of the following are layers in the TCP/IP model? (Choose three.)
A. Application
B. Session
C. Transport
D. Internet
E. Data Link
F. Physical

Back 15

A, C, D. This seems like a hard question at first because it doesn’t make sense. The listed
answers are from the OSI model and the question asked about the TCP/IP protocol stack (DoD
model). However, let’s just look for what is wrong. First, the Session layer is not in the TCP/
IP model; neither are the Data Link and Physical layers. This leaves us with the Transport layer
(Host-to-Host in the DoD model), Internet layer (Network layer in the OSI), and Application
layer (Application/Process in the DoD).

Front 16

Which class of IP address provides a maximum of only 254 host addresses per network ID?
A. Class A
B. Class B
C. Class C
D. Class D
E. Class E

Back 16

C. A Class C network address has only 8 bits for defining hosts: 28 – 2 = 254.

Front 17

Which of the following describe the DHCP Discover message? (Choose two.)
A. It uses FF:FF:FF:FF:FF:FF as a layer 2 broadcast.
B. It uses UDP as the Transport layer protocol.
C. It uses TCP as the Transport layer protocol.
D. It does not use a layer 2 destination address.

Back 17

A, B. A client that sends out a DHCP Discover message in order to receive an IP address
sends out a broadcast at both layer 2 and layer 3. The layer 2 broadcast is all Fs in hex, or
FF:FF:FF:FF:FF:FF. The layer 3 broadcast is 255.255.255.255, which means all networks and
all hosts. DHCP is connectionless, which means it uses User Datagram Protocol (UDP) at the
Transport layer, also called the Host-to-Host layer.

Front 18

Which layer 4 protocol is used for a Telnet connection?
A. IP
B. TCP
C. TCP/IP
D. UDP
E. ICMP

Back 18

B. Although Telnet does use TCP and IP (TCP/IP), the question specifically asks about layer 4,
and IP works at layer 3. Telnet uses TCP at layer 4.

Front 19

Which statements are true regarding ICMP packets? (Choose two.)
A. They acknowledge receipt of a TCP segment.
B. They guarantee datagram delivery.
C. They can provide hosts with information about network problems.
D. They are encapsulated within IP datagrams.
E. They are encapsulated within UDP datagrams.

Back 19

C, D. Internet Control Message Protocol (ICMP) is used to send error messages through the
network, but they do not work alone. Every segment or ICMP payload must be encapsulated
within an IP datagram (or packet).

Front 20

10. Which of the following services use TCP? (Choose three.)
A. DHCP
B. SMTP
C. SNMP
D. FTP
E. HTTP
F. TFTP

Back 20

B, D, E. SMTP, FTP, and HTTP use TCP.

Front 21

Which of the following services use UDP? (Choose three.)
A. DHCP
B. SMTP
C. SNMP
D. FTP
E. HTTP
F. TFTP

Back 21

11. A, C, F. Explanation:DHCP, SNMP, and TFTP use UDP. SMTP, FTP, and HTTP use TCP.

Front 22

12. Which of the following are TCP/IP protocols used at the Application layer of the OSI model?
(Choose three.)
A. IP
B. TCP
C. Telnet
D. FTP
E. TFTP

Back 22

C, D, E. Telnet, File Transfer Protocol (FTP), and Trivial FTP (TFTP) are all Application layer
protocols. IP is a Network layer protocol. Transmission Control Protocol (TCP) is a Transport
layer protocol.

Front 23

If you use either Telnet or FTP, which is the highest layer you are using to transmit data?
A. Application
B. Presentation
C. Session
D. Transport

Back 23

A. Both FTP and Telnet use TCP at the Transport layer; however, they both are Application
layer protocols, so the Application layer is the best answer for this question.

Front 24

The DoD model (also called the TCP/IP stack) has four layers. Which layer of the DoD model
is equivalent to the Network layer of the OSI model?
A. Application
B. Host-to-Host
C. Internet
D. Network Access

Back 24

C. The four layers of the DoD model are Application/Process, Host-to-Host, Internet, and Network
Access. The Internet layer is equivalent to the Network layer of the OSI model.

Front 25

Which two of the following are private IP addresses?
A. 12.0.0.1
B. 168.172.19.39
C. 172.20.14.36
D. 172.33.194.30
E. 192.168.24.43

Back 25

C, E. Class A private address range is 10.0.0.0 through 10.255.255.255. Class B private
address range is 172.16.0.0 through 172.31.255.255, and Class C private address range is
192.168.0.0 through 192.168.255.255.

Front 26

What layer in the TCP/IP stack is equivalent to the Transport layer of the OSI model?
A. Application
B. Host-to-Host
C. Internet
D. Network Access

Back 26

B. The four layers of the TCP/IP stack (also called the DoD model) are Application/Process,
Host-to-Host, Internet, and Network Access. The Host-to-Host layer is equivalent to the
Transport layer of the OSI model.

Front 27

Which statements are true regarding ICMP packets? (Choose two)
A. ICMP guarantees datagram delivery.
B. ICMP can provide hosts with information about network problems.
C. ICMP is encapsulated within IP datagrams.
D. ICMP is encapsulated within UDP datagrams.

Back 27

B, C. ICMP is used for diagnostics and destination unreachable messages. ICMP is encapsulated
within IP datagrams, and because it is used for diagnostics, it will provide hosts with
information about network problems.

Front 28

What is the address range of a Class B network address in binary?
A. 01xxxxxx
B. 0xxxxxxx
C. 10xxxxxx
D. 110xxxxx

Back 28

C. The range of a Class B network address is 128–191. This makes our binary range
10xxxxxx.

Front 29

20. Which of the following protocols uses both TCP and UDP?
A. FTP
B. SMTP
C. Telnet
D. DNS

Back 29

D. DNS uses TCP for zone exchanges between servers and UDP when a client is trying to
resolve a hostname to an IP address.

Front 30

Process/Application Layer Protocols and programs.

Back 30

Telnet is a terminal emulation program
that allows you to log into a remote host and run programs. File Transfer Protocol (FTP) is a
connection-oriented service that allows you to transfer files. Trivial FTP (TFTP) is a connectionless
file transfer program. Simple Mail Transfer Protocol (SMTP) is a send-mail program.

Front 31

Host-to-Host layer protocols

Back 31

Transmission Control Protocol (TCP) is a
connection-oriented protocol that provides reliable network service by using acknowledgments
and flow control. User Datagram Protocol (UDP) is a connectionless protocol that provides
low overhead and is considered unreliable.

Front 32

Internet layer protocols.

Back 32

Internet layer protocols. Internet Protocol (IP) is a connectionless protocol
that provides network address and routing through an internetwork. Address Resolution Protocol
(ARP) finds a hardware address from a known IP address. Reverse ARP (RARP) finds
an IP address from a known hardware address. Internet Control Message Protocol (ICMP)
provides diagnostics and destination unreachable messages.

Front 33

Class A range.

Back 33

The IP range for a Class A network is 1–126. This provides 8
bits of network addressing and 24 bits of host addressing by default.

Front 34

Class B range.

Back 34

The IP range for a Class B network is 128–191. Class B
addressing provides 16 bits of network addressing and 16 bits of host addressing by default.

Front 35

Class C range.

Back 35

The IP range for a Class C network is 192–223. Class C
addressing provides 24 bits of network addressing and 8 bits of host addressing by default.

Front 36

Private IP ranges.

Back 36

Class A -> 10.0.0.0
through 10.255.255.255.
Class B -> 172.16.0.0 through 172.31.255.255.
Class C -> 192.168.0.0 through 192.168.255.255.