Ports & Protocols

Question 1

Explain TCP

Answer 1

Transmission Control Protocol
3 way handshake
Source sends a syn request to destination
Destination sends acknowledgement and syn to Source
Source sends acknowledgement back to destination

Question 2

Explain UDP

Answer 2

User Diagram Protocol
Fast but not reliable
Source just stands data to destination

Question 3

Explain FTP

Answer 3

File Transfer Protocol
Port 20/21 - 20 data/21 auth connection
TCP
plain text

Question 4

Explain SSH

Answer 4

Secure Shell
Encrypted CLI
Port: 22
TCP
SCP (secure copy) and SFTP (ssh file transfer)
linix/unix

Question 5

Explain Telnet

Answer 5

Plain Text CLI
Port: 23
TCP

Question 6

Explain TACACS

Answer 6

Network Access Control
Always encrypted
Port: 49
Either TCP or UDP

Question 7

Explain DNS

Answer 7

Domain Name Server
53 UDP used for queries (name to IP)
53 TCP zone transfer

Question 8

Explain HTTP

Answer 8

Hyper-Text Transfer Protocol
TCP Port: 80
Web traffic, plain text

HTTPS on 443 secure option

Question 9

Explain Kerberos

Answer 9

Network Authentication (SSO)
Port: 88
Either TCP or UDP

Question 10

Explain POP3

Answer 10

Post Office Protocol
Incoming email, plain text
Port: 110
TCP

Question 11

Explain NTP

Answer 11

Network Time Protocol
Port: 123
UDP

Question 12

Explain SMB

Answer 12

Server Message Block
Net BIOS
Port: 137-139 and 445
Either UDP or TCP

Question 13

Explain IMAP

Answer 13

Internet Message Access Protocol
Incoming email
Port: 143
TCP
Allows syncing across multiple devices (unlike POP3)
Plain text

IMAPS on 993 is secure option

Question 14

Explain SNMP

Answer 14

Simple Network Management Protocol
v1, v2, v3
Port: 161-162
UDP
Encrypted

Question 15

Explain LDAP

Answer 15

Lightweight Directory Access Protocol
Port: 389
Plain text
Either UDP or TCP

Question 16

Explain HTTPS

Answer 16

Hyper-Text Transfer Protocol Secure
Port: 443
TCP
Encrypted w SSL/TLS
v1, v1.1, v1.2, v1.3 (1.2 or 1.3 on exam)

Question 17

Explain SMTPS

Answer 17

Simple Mail Transfer Protocol
Outgoing mail encryption SSL/TLS
Port: 587
TCP

Question 18

Explain LDAPS

Answer 18

Lightweight Directory Access Secure
SSL/TLS
Port: 636
TCP

Question 19

Explain IMAPS

Answer 19

Internet Message Access Protocol Secure
SSL/TLS
Port: 993
TCP

Question 20

Explain POP3S

Answer 20

Post Office Protocol Secure
Incoming email encrypt SSL/TLS
Port: 995
TCP

Question 21

Explain RADIUS

Answer 21

Remote Authentication Dial-In User Protocol
Centralized AAA
Port: 1812-1813
UDP

Question 22

Explain RDP

Answer 22

Remote Desktop Protocol
Built into Windows, Encrypted
Port: 3389
TCP