Netstat

Chapter 2 Solutions

Review Questions

1. The Netstat command indicates that POP3 is in use on a remote server. Which port is the remote server most likely using?

b. Port 110

2. On a Windows computer, what command can you enter to show all open ports being used?

a. Netstat

3. Which protocol uses UDP?

d. TFTP

4. Which protocol offers guaranteed delivery and is connection oriented?

c. TCP

5. TCP communication could be likened to which of the following?

d. Phone conversation

6. Which of the following protocols is connectionless? (Choose all that apply.)

a. UDP

b. IP

7. Which command verifies the existence of a node on a network?

a. Ping

8. FTP offers more security than TFTP. True or False?

True

9. List the three components of the TCP/IP three-way handshake.

SYN, SYN-ACK, and ACK

10. What protocol is used for reporting or informational purposes?

c. ICMP

11. List the six flags of a TCP packet.

SYN, ACK, PSH, URG, RST, FIN

12. A UDP packet is usually smaller than a TCP packet. True or False?

True

13. What port, other than port 110, is used to retrieve e-mail?

b. Port 143

14. What port does DNS use?

d. Port 53

15. What command is used to log on to a remote server, computer, or router?

c. Telnet

16. Which of the following is not a valid octal number?

c. 3482

17. The initial sequence number (ISN) is set at which step of the TCP three-way handshake?

d. 1 and 2

18. A Ping command initially uses which ICMP type code?

b. Type 8

19. “Destination Unreachable” is designated by which ICMP type code?

c. Type 3

20. What’s the hexadecimal equivalent of the binary number 1111 1111?

a. FF

Activities

Activity 2-4

1. Octal values