2.1 - Common Network Ports

Question 1

What are well-known port numbers used for?

Answer 1

They are used by services so that both the server and client know what port number to use for communication, and they are also important for firewalls.

Question 2

What are the two port numbers used by FTP?

Answer 2

TCP port 20 for data transfers and TCP port 21 for control.

Question 3

What does SSH use for communication?

Answer 3

TCP port 22.

Question 4

What port does Telnet use for communication?

Answer 4

TCP port 23.

Question 5

What is a major security difference between SSH and Telnet?

Answer 5

SSH encrypts data while Telnet does not.

Question 6

What port does SMTP use?

Answer 6

TCP port 25.

Question 7

What ports are commonly used by DHCP?

Answer 7

UDP port 67 for the server and UDP port 68 for the client.

Question 8

What does DNS use for communication?

Answer 8

UDP port 53.

Question 9

What ports does HTTP use?

Answer 9

TCP port 80.

Question 10

What ports does HTTPS use?

Answer 10

TCP port 443.

Question 11

What port does POP3 use?

Answer 11

TCP port 110.

Question 12

What port does IMAP use?

Answer 12

TCP port 143.

Question 13

What protocol is commonly used by Windows for file and print sharing?

Answer 13

SMB (Server Message Block).

Question 14

What port does NetBIOS use for name service?

Answer 14

UDP port 137.

Question 15

What port does NetBIOS use for session setup and data transfer?

Answer 15

TCP port 139.

Question 16

What port does SMB use for direct TCP/IP communication?

Answer 16

TCP port 445.

Question 17

What ports does SNMP use for queries and traps?

Answer 17

UDP port 161 for queries and UDP port 162 for traps.

Question 18

What version of SNMP includes encryption for data integrity and authentication?

Answer 18

SNMP v3.

Question 19

What port does LDAP use?

Answer 19

TCP port 389.

Question 20

What port does RDP use?

Answer 20

TCP port 3389.