Chapter 9: TCP/IP Applications

Question 1

Session

Answer 1

A logical stream of data flowing between two programs over a network.

Question 2

Transmission Control Protocol (TCP)

Answer 2

• Enables connection-oriented communication in networks that use the TCP/IP protocol suite.
• Most common type of session

Question 3

TCP Three-Way Handshake

Answer 3

A three-packet conversation between TCP hosts to establish and start a data transfer session.

Question 4

User Datagram Protocol (UDP)

Answer 4

Used for the type of sessions that don’t require the overhead of connection-oriented traffic.

Question 5

Port and Session Type of DHCP

Answer 5

Port 67 (server) and port 68 (client)
UDP

Question 6

Network Time Protocol (NTP)

Answer 6

Synchronizes the clocks of devices on a network.

UDP port 123

Question 7

Trivial File Transfer Protocol (TFTP)

Answer 7

Enables you to transfer files from one machine to another.

UDP port 69

Question 8

Internet Control Message Protocol (ICMP)

Answer 8

• Used to handle many low level functions such as error reporting.
• Usually request and response pairs

Question 9

What kind of packets does ping send?

Answer 9

ICMP

Question 10

What is the packet called that ping sends out? The one that comes back?

Answer 10

Echo request, Echo reply

Question 11

If your computer has no route to the address listed, ping will display _________.

Answer 11

Destination Host Unreachable

Question 12

If you ping a device and no echo reply comes back before the 1-second default time, ping will respond with _______.

Answer 12

Request Timed Out

Question 13

Ping of Death

Answer 13

A ping that allowed malicious users to send malformed ping packets to your computer and make it crash.

Question 14

Internet Group Management Protocol (IGMP)

Answer 14

Enables routers to communicate with hosts to determine a “group” membership for multicasting.

Question 15

What is the subnet that multicast addresses use?

Answer 15

224.0.0.0/4

Question 16

Well-known Port Numbers

Answer 16

0-1023

Reserved for specific TCP/IP applications

Question 17

Ephemeral Ports

Answer 17

1024-5000
An arbitrary number generated by a sending computer that the receiving computer uses as a destination address when sending a return packet.

Question 18

Dynamic/Private Port Numbers

Answer 18

49152-65535

Recommended by IANA to use as ephemeral port numbers

Question 19

Registered Ports

Answer 19

1024-49151

The IANA assigns these ports for anyone to use for their application

Question 20

Socket

Answer 20

A combination of a port number and an IP address that uniquely identifies a connection.

Question 21

Endpoints

Answer 21

The term used when discussing the data each computer stores about the connection between two computers’ TCP/IP applications.

Question 22

netstat

Answer 22

Shows you the list of endpoints you have connections with.

Question 23

netstat -a

Answer 23

Tells netstat to show all used ports

Question 24

netstat -n

Answer 24

Tells netstat to show raw port #’s and IP addresses.

Question 25

netstat -o

Answer 25

Tells netstat to show the process ID

Question 26

netstat -b

Answer 26

Shows the name of the running program

Question 27

Open Port

Answer 27

A socket that is prepared to respond to any IP packets destined for that socket’s port number.

Question 28

Established Port

Answer 28

Active, working endpoint

Question 29

close_wait

Answer 29

Implies that a graceful closure is happening, i.e. each side see the session closing normally

Question 30

time_wait

Answer 30

Means a connection has been lost and is waiting a defined amount of time called a timeout period.

Question 31

ps

Answer 31

Linux command that shows process IDs

Question 32

Hypertext Transfer Protocol (HTTP)

Answer 32

Defines what actions Web servers and browsers should take in response to various commands.
TCP port 80

Question 33

Web Server

Answer 33

• A computer that delivers Web pages.

- Listen on port 80

Question 34

Internet Information Services (IIS)

Answer 34

• Microsoft’s Web server program for managing Web servers.

- Enables you to set a max connection limit on your Web server based on available bandwidth and memory

Question 35

Apache HTTP Server

Answer 35

The web server that most UNIX/Linux based operating systems use.

Question 36

What are the three qualities of a secure Internet application?

Answer 36

1) Authentication
2) Encryption
3) Nonrepudiation:Process of making sure data came from the person or entity it was supposed to come from.

Question 37

Secure Sockets Layer (SSL)

Answer 37

A protocol developed for transmitting private documents over the Internet

Question 38

HTTPS

Answer 38

• The secure form of HTTP

- TCP Port 443

Question 39

Telnet

Answer 39

• The first protocol invented to connect remotely to another computer.
• TCP Port 23

Question 40

Secure Shell (SSH)

Answer 40

Like Telnet, but encrypted.

-TCP Port 22

Question 41

Simple Mail Transfer Protocol (SMTP)

Answer 41

Used by email clients to send messages

TCP Port 25

Question 42

Post Office Protocol version 3 (POP3)

Answer 42

Used to receive mail

TCP Port 110

Question 43

Internet Message Access Protocol version 4 (IMAP4)

Answer 43

Preferred alternative to POP3 for receiving mail

TCP Port 143

Question 44

File Transfer Protocol (FTP)

Answer 44

-The original protocol for transferring files on the Internet.
-Not encrypted
TCP port 20/21