Protocol and Port

Question 1

What port and protocol does DNS use? Also, what layer of the OSI model does DNS operate at?

Answer 1

Port 53 over TCP/UDP, and DNS operates at Layer 7 of the OSI model.

Question 2

What port and protocol does IMAP use? Also, what layer of the OSI model does IMAP operate at?

Answer 2

Port 143 over TCP, and IMAP operates at Layer 7 of the OSI model. Used for email clients to retrieve email from an email server.

Question 3

**What port and protocol does POP use? Also, what layer of the OSI model does POP operate at?

Answer 3

Port 110 over TCP, and POP operates at Layer 7 of the OSI model. Used for clients to download emails from an email server.

Question 4

**What port and protocol does SMTP use? Also, what layer of the OSI model does SMTP operate at?

Answer 4

Port 25 over TCP, and SMTP operates at Layer 7 of the OSI model.

Question 5

What port and protocol does FTP use? Also, what layer of the OSI model does FTP operate at?

Answer 5

Port 20/21 over TCP, and FTP operates at Layer 7 of the OSI model.

Question 6

What port and protocol does SSH use? Also, what layer of the OSI model does SSH operate at?

Answer 6

Port 22 over TCP, and SSH operates at Layer 7 of the OSI model.

Question 7

What port and protocol does SFTP use? Also, what layer of the OSI model does SFTP operate at?

Answer 7

Port 22 over TCP, and SFTP operates at Layer 7 of the OSI model.

Question 8

What port and protocol does TFTP use? Also, what layer of the OSI model does TFTP operate at?

Answer 8

Port 69 over TCP, and SFTP operates at Layer 7 of the OSI model.

Question 9

What port and protocol does Telnet use? Also, what layer of the OSI model does Telnet operate at?

Answer 9

Port 23 over TCP, and Telnet operates at Layer 7 of the OSI model.

Question 10

What port and protocol does DHCP use? Also, what layer of the OSI model does DHCP operate at?

Answer 10

Port 67/68 over UDP, and DHCP operates at Layer 7 of the OSI model.

Question 11

What port and protocol does HTTP use? Also, what layer of the OSI model does HTTP operate at?

Answer 11

Port 80 over TCP, and HTTP operates at Layer 7 of the OSI model.

Question 12

What port and protocol does HTTPS use? Also, what layer of the OSI model does HTTPS operate at?

Answer 12

Port 443 over TCP, and HTTPS operates at Layer 7 of the OSI model.

Question 13

**What port and protocol does SNMP use? Also, what layer of the OSI model does SNMP operate at?

Answer 13

Port 161 over TCP, and SNMP operates at Layer 7 of the OSI model.

Question 14

**What port and protocol does RDP use? Also, what layer of the OSI model does RDP operate at?

Answer 14

Port 3389 over TCP/UDP, and RDP operates at Layer 7 of the OSI model.

Question 15

**What port and protocol does NTP use? Also, what layer of the OSI model does NTP operate at?

Answer 15

Port 123 over UDP, and NTP operates at Layer 7 of the OSI model.

Question 16

What port and protocol does SIP use? Also, what layer of the OSI model does SIP operate at?

Answer 16

Port 5060/5061 over TCP/UDP, and SIP operates at Layer 7 of the OSI model.

Question 17

**What port and protocol does SMB use? Also, what layer of the OSI model does SMB operate at?

Answer 17

Port 445 over TCP, and SMB operates at Layer 5 of the OSI model. Used for sharing access to files, printers, serial ports (to name a few) which are on a network.

Question 18

**What port and protocol does LDAP use? Also, what layer of the OSI model does LDAP operate at?

Answer 18

Port 389 over TCP/UDP, and LDAP operates at Layer 7 of the OSI model.

Question 19

**What port and protocol does LDAPS use? Also, what layer of the OSI model does LDAPS operate at?

Answer 19

Port 636 over TCP/UDP, and LDAPS operates at Layer 7 of the OSI model.

Question 20

**What port and protocol does H.323 use? Also, what layer of the OSI model does H.323 operate at?

Answer 20

Port 1720 over TCP/UDP, and LDAP operates at Layer 7 of the OSI model.