Ports & Protocols

Question 1

DNS - TCP/UDP Port 53

Answer 1

Domain Name Service - TCP/UDP Port 53

Hierarchical, decentralized, naming system for computers, services, or other internet resources. Converts domain names to IP addresses (vice versa).

Question 2

SSH - TCP Port 22

Answer 2

Secure Shell - TCP Port 22

Cryptographic protocol (asymmetric) for operating securely over an unsecured network. Best known for remote login to computer systems.

Question 3

TELNET - TCP Port 23

Answer 3

TCP Port 23

Very insecure remote login, do not use

Question 4

LDAP - TCP/UDP Port 389

Answer 4

Lightweight Directory Access Protocol - TCP/UDP Port 389

Open, vendor-neutral, industry standard for accessing and maintaining distributed directory information services.

Question 5

LDAPS - TCP Port 636 & 3269

Answer 5

Lightweight Directory Access Protocol Secure - TCP Port 636

Secure version of LDAP. Uses TLS

Question 6

FTP - TCP Port 20 & 21

Answer 6

File Transfer Protocol - TCP Port 20 & 21

Transfers files on a network. Unsecure (in the clear)

Question 7

FTPS - TCP Port 989 & 990

Answer 7

File Transfer Protocol Secure - TCP Port 989 & 990

Question 8

SFTP - TCP Port 22

Answer 8

Secure Shell FTP - TCP Port 22

Uses FTP encrypting with SSH

Question 9

SNMPv3 - UDP Port 161

Answer 9

Simple Network Management Protocol v3 - UDP Port 161

Provides collection and organization of information about managed devices on IP network.

Question 10

HTTP - TCP/UPD Port 80

Answer 10

Hypertext Transfer Protocol - TCP/UPD Port 80

The foundation of communications on the world wide web. Designed for use for most devices. Unsecured web browsing.

Question 11

HTTPS - TCP/UDP Port 443

Answer 11

Hypertext Transfer Protocol Secure - TCP/UDP Port 443

Foundation of ecommerce on the web. Designed for adding security to HTTP.

Question 12

POP3 - TCP Port 110

Answer 12

Post Office Protocol v3 - TCP Port 110

Used to download emails from a remote server via TCP/IP.

Question 13

Secure POP - TCP Port 995

Answer 13

Secure Post Office Protocol - TCP Port 995

Question 14

IMAP - TCP/UDP Port 143

Answer 14

Internet Message Access Protocol - TCP/UDP Port 143

Allows email retrieval from a mail server. Also allows user to manipulate the messages on the server, as if they are stored locally. Used more than POP3 because of its more advanced features. Also keeps all devices email synchronized, POP3 does not.

Question 15

Secure IMAP - TCP/UDP Port 993

Answer 15

Secure Internet Message Access Protocol - TCP/UDP Port 993

Question 16

SMTP - TCP Port 25

Answer 16

Simple Mail Transfer Protocol - TCP Port 25

(Think of SMTP as Send Mail)

Internet standard for “sending” email

Question 17

TLS SMTP - TCP Port 465

Answer 17

Simple Mail Transfer Protocol using TLS - TCP Port 465

Question 18

NTP - UDP Port 123

Answer 18

Network Time Protocol - UDP Port 123

Provides clock synchronization between computers.

Question 19

TACACS+ - TCP Port 49

Answer 19

Terminal Access Controller Access Control System+ - TCP Port 49

Question 20

RADIUS - UDP Port 1812 & 1813

Answer 20

Remote Authentication Dial-In User Service - UDP Port 1812 & 1813

Question 21

DHCP - Port 67, 68

Answer 21

Dynamic Host Control Port
Port 67, 68

Dynamically assigns an IP address and other network config settings to a client, and enables automatic requests for IP addresses.

Question 22

TFTP - Port 69

Answer 22

Trivial File Transfer Protocol - Port 69

Transmits files in both directions and is used for booting an OS from a LAN file server, from an application.

Question 23

NetBIOS - Port 139

Answer 23

Network Basic Input/Output System. - Port 139

Service allowing applications on different computers to communicate for file and printer sharing. Works together with Server Message Block (SMB). This one handles authentication.

Question 24

SMB - Port 445

Answer 24

Server Message Block - Port 445

Provides shared access to files, printers, and misc. between devices on a network. Works together with NetBIOS. This one handles file sharing.

Question 25

RDP - Port 3389

Answer 25

Remote Desktop Protocol - Port 3389

Microsoft protocol which provides graphical interface to connect to another computer via network.

Question 26

SIP - Port 5060, 5061

Answer 26

Session Initiation Protocol - Port 5060, 5061

Used for VOIP, Video Calls, Instant Messaging. Opens, maintains, and closes the