Ports to Know

Question 1

Well Known Ports

Answer 1

0-1,023

Question 2

Registered Ports

Answer 2

1024-49151

Question 3

Dynamic/Private Ports

Answer 3

49152-65535

Question 4

Port 20

Answer 4

FTP - File Transfer Protocol – sending data - TCP

Question 5

Port 21

Answer 5

FTP - File Transfer Protocol - Control communications - TCP

Question 6

Port 22

Answer 6

– SSH – Secure Shell – Login to devices remotely, console access, encrypted - TCP

Question 7

Port 23

Answer 7

Telnet – Login to devices remotely, console access, no encryption - TCP

Question 8

Port 25

Answer 8

SMTP – Simple Mail Transfer Protocol – Used for Sending email Server to server; also used to send mail from a device to mail server (commonly used on mobile devices) - TCP

Question 9

Port 53

Answer 9

DNS – Domain Name System – Converts Names to IP addresses - UDP

Question 10

Port 67

Answer 10

DHCP – Dynamic Host Configuration Protocol – For clients, Automated configuration of IP address, subnet mask, requires a DHCP server - UDP

Question 11

Port 68

Answer 11

DHCP – Dynamic Host Configuration Protocol – For servers, Automated configuration of IP address, subnet mask, requires a DHCP server - UDP

Question 12

Port 80

Answer 12

HTTP – Hyper Text Transfer Protocol – Web Server Communication (Web Browser) - TCP

Question 13

Port 110

Answer 13

POP3 – Post Office Protocol version 3 – Receive e-mails from an e-mail server (authenticate and transfer), basic mail transfer functionality - TCP

Question 14

Port 137

Answer 14

NetBIOS name services (nbname) - UDP

Question 15

Port 138

Answer 15

NetBIOS datagram service (nbdatagram) - UDP

Question 16

Port 139

Answer 16

NetBIOS sessions service (nbsession) - TCP

Question 17

Port 143

Answer 17

IMAP4 – Internet Message Access Protocol v4 – Includes management of email inbox from multiple clients. Can access email from multiple devices - TCP

Question 18

Port 161

Answer 18

SNMP – Simple Network Management Protocol – Queries. Gather statistics from network devices - UDP

Question 19

Port 162

Answer 19

SNMP - Simple Network Management Protocol – Traps. Gather statistics from network - UDP

Question 20

Port 389

Answer 20

LDAP – Lightweight Directory Access Protocol – Store all credentials in one centralized database as well as retrieve said info. Store and retrieve in a network directory (commonly used in Microsoft Active Directory) - TCP

Question 21

Port 427

Answer 21

SLP – Service Location Protocol – Populates list of available devices - TCP/UDP

Question 22

Port 443

Answer 22

HTTPS – Hypertext Transfer Protocol Secure – SSL/TLS encryption. Web server communication with encryption - TCP

Question 23

Port 445

Answer 23

SMB/CIFS – Server Message Block/Common Internet File System – File sharing, printer sharing, Direct SMB communication without NetBIOS transport - TCP

Question 24

Port 465

Answer 24

SMTPS – SMTP with SSL/TLS encryption - TCP

Question 25

Port 548

Answer 25

AFP – Apple Filing Protocol – File services (copy,rename,move files) in macOS, works with SLP - TCP

Question 26

Port 989

Answer 26

FTPS – File Transfer Protocol Secure – SSL/TLS encryption. Data Connection/sending data - TCP

Question 27

Port 990

Answer 27

FTPS – File Transfer Protocol Secure –SSL/TLS encryption. Control connection/communication - TCP

Question 28

Port 993

Answer 28

– IMAP4S – Internet Message Access Protocol Secure – Same as IMAP4 but uses SSL/TLS encryption - TCP

Question 29

Port 995

Answer 29

– POP3S – Post Office Protocol v3 Secure – POP3 with SSL/TLS encryption - TCP

Question 30

Port 3389

Answer 30

RDP – Remote Desktop Protocol – Share a desktop from a remote location, can connect to an entire desktop or single application - TCP