Common Ports

Question 1

SSH

Answer 1

22, Encrypted TELNET.

Question 2

DNS

Answer 2

53, Domain Name System. Converts names into IP addresses.

Question 3

SMTP

Answer 3

25, Simple Mail Transfer Protocol. Server to server and device to server email transfer. Commonly on mobile devices.

Question 4

SFTP

Answer 4

22, Secure FTP. Transfers files better than FTP.

Question 5

FTP

Answer 5

20 and 21, Non-encrypted file transfer.

Question 6

TFTP

Answer 6

69, Trivial FTP. Very simple file transfer. No authentication or encryption.

Question 7

TELNET

Answer 7

23, Remotely logs into other devices and access them through text based console. No encryption.

Question 8

DHCP

Answer 8

67 and 68, Dynamic Host Control Protocol. Automated configuration of IP address, subnet mask, and others.

Question 9

HTTP

Answer 9

80, Hypertext Transfer Protocol. Web server communication.

Question 10

HTTPS

Answer 10

443, Secure HTTP. Encrypted web server communication.

Question 11

SNMP

Answer 11

161, Simple Network Management Protocol. Gather statistics from network devices.

Question 12

RDP

Answer 12

3389, Remote Desktop Protocol. Share desktop or application from a remote location.

Question 13

NTP

Answer 13

123, Network Time Protocol. Determines time on network devices and synchronizes them.

Question 14

SIP

Answer 14

5060 and 5061, Session Initiation Protocol. Voice over IP signaling. Set up and manage VoIP sessions.

Question 15

SMB

Answer 15

445, Server Message Block. File and Printer sharing for Windows devices.

Question 16

POP

Answer 16

110, Post Office Protocol. Receive emails from an email server.

Question 17

IMAP

Answer 17

443, Internet Message Access Protocol. Manages email inbox for multiple clients.

Question 18

LDAP

Answer 18

389, Lightweight Directory Access Protocol. Store and retrieve information in a network directory.

Question 19

LDAPS

Answer 19

636, LDAP Secure.

Question 20

H.323

Answer 20

1720, Old VoIP session manager. Can do the same things as SIP.