TCP/IP Applications

Question 1

session

Answer 1

any communication between one computer and another

Question 2

TCP

Answer 2

Transmission Control Protocol

- enables connection oriented communications in networks that use TCP/IP protocol suite

Question 3

How does TCP connect

Answer 3

TCP three-way handshake

• client send single SYN segment to server
• server return a single SYN, ACK segment
• client sends single ACK segment and request server begins sending data
• once server finishes, sends a FIN segment
• client responds with ACK, then sends FIN
• server responds with ACK
• both parties consider session closed

Question 4

DHCP ports

Answer 4

UDP 67 for client

UDP 68 for server

Question 5

Synchronize time

Answer 5

NTP - Network Time Protocol
SNTP - Simple Network Time Protocol
Both use UDP 123

Question 6

TFTP

Answer 6

Trivial File Transfer Protocol

• UDP port 69
• only used on same LAN

Question 7

ICMP

Answer 7

Internet Control Message Protocol

• works at layer 3
• UDP
• ping is an example

Question 8

What is the reply to a ping request called?

Answer 8

echo reply

Question 9

ping of death

Answer 9

sending a malformed ping packet to cause destination computer to crash

Question 10

IGMP

Answer 10

Internet Group Managment Protocol

- enables routers to communicate with hosts to determine a group “memebership”

Question 11

port number

Answer 11

• 16 bit value
• between 0 and 65535
• 0 to 1023 are well-known port numbers (reserved for specific applications)
• 1024 to 5000 are ephemeral port numbers
• 49152 to 65535 are dynamic or private port numbers

Question 12

Session information (IP address and port number) are stored in?

Answer 12

socket or endpoint

Question 13

Session data stored for two computers about the same connection

Answer 13

socket pairs or endpoints

Question 14

Term for session information and session data

Answer 14

connection or session

Question 15

View endpoints on Windows CLI

Answer 15

netstat -n

Question 16

a socket that is prepared to respond to any IP packets destined for that port

Answer 16

open port or listening port

Question 17

View open ports on Windows CLI

Answer 17

netstat -an

Question 18

netstat states

Answer 18

listening - open, waiting for connection
established - port is connected
close_wait - closed

Question 19

View process IDs in netstat

Answer 19

netstat -o

Question 20

View program names in netstat

Answer 20

netstat -b

Question 21

find process ID in linux

Answer 21

ps

Question 22

Why set a connection limit on IIS

Answer 22

• based on avialable memory and bandwidth

- prevent DOS attacks

Question 23

URL

Answer 23

Uniform Resource Locator

Question 24

What does an internet application need to be secure?

Answer 24

authentication - user names and passwords
encryption - stirring up the data
nonrepudiation - source is not able to deny a sent message

Question 25

SSL/TLS

Answer 25

Secure Sockets Layer / Tranport Layer Security

Question 26

HTTPS port

Answer 26

TCP 443

Question 27

Telnet port

Answer 27

TCP 23

Question 28

SSH port

Answer 28

TCP 22

Question 29

SMTP port

Answer 29

TCP 25

Question 30

POP3 port

Answer 30

TCP 110

Question 31

IMAP4 port

Answer 31

TCP 143

Question 32

3 main email servers

Answer 32

Exim, postfix and exchange

Question 33

FTP port

Answer 33

TCP ports 21 and 20 passive FTP only uses port 21 use passive FTP with NAT

Question 34

TFTP port

Answer 34

UDP port 69

Question 35

Protocol developed by netscape for transmitting private documents

Answer 35

SSL

Question 36

netstat show all used ports

Answer 36

netstat -a

Question 37

netstat show raw port numbers and ip addresses

Answer 37

netstat -n