1.1 Common Ports

Question 1

SSH uses port _________________.

Answer 1

TCP/22

Question 2

DNS uses port _________________.

Answer 2

UDP/53

Question 3

SMTP uses port _________________.

Answer 3

TCP/25

Question 4

SFTP uses port _________________.

Answer 4

TCP/22

Question 5

FTP uses port _________________.

Answer 5

TCP/20 active mode

TCP/21 control

Question 6

Telnet uses port _________________.

Answer 6

TCP/23

Question 7

DHCP uses port _________________.

Answer 7

UDP/67

UDP/68 - Requires a DHCP server

Question 8

TFTP uses port _________________.

Answer 8

UDP/69

Question 9

HTTP uses port _________________..

Answer 9

TCP/80

Question 10

HTTPS uses port _________________.

Answer 10

TCP/443

Question 11

SNMP uses port _________________.

Answer 11

UDP/161

Question 12

RDP uses port _________________.

Answer 12

TCP/3389

Question 13

NTP uses port _________________.

Answer 13

UDP/123

Question 14

SIP uses port _________________.

Answer 14

TCP/5060-5061

Question 15

SMB uses port _________________.

Answer 15

TCP/445

Question 16

POP3 uses port _________________.

Answer 16

TCP/110

Question 17

IMAP4 uses port _________________.

Answer 17

TCP/143

Question 18

LDAP uses port _________________.

Answer 18

TCP/389

Question 19

LDAPS uses port _________________.

Answer 19

TCP/636

Question 20

H.323 uses port _________________.

Answer 20

TCP/1720

Question 21

Describe SSH

Answer 21

Secure Shell

TCP 22

Looks and acts the same as Telnet, but encrypted

Allows you to log in and control devices via commands

Question 22

Describe DNS

Answer 22

Domain Name System

UDP 53

Converts names to IP addresses

Question 23

Describe SMTP

Answer 23

Simple Mail Transfer Protocol

TCP 25

Internet standard for sending mail

Also used to send mail from a device to a mail server

Question 24

Describe SFTP

Answer 24

Secure Shell File Transfer Protocol

TCP 22

Uses the SSH File Transfer Protocol tunnel

Provides file system functionality

Resuming interrupted transfers, directory listings, remote file removal.

Question 25

Describe FTP

Answer 25

Transfers files between systems TCP 20, 21 Authenticates with a username and password We don't use it because it is not encrypted.

Question 26

Describe Telnet

Answer 26

Telecommunication Network TCP 23 Not encrypted, insecure Remote access command prompt Console access In-the-clear communication, no encryption Not the best choice for production systems

Question 27

Describe DHCP

Answer 27

Dynamic Host Configuration Protocol UDP 67, 68 Automated configuration of IP address, subnet mask, and other options. Addresses are assigned by MAC address

Question 28

Describe SNMP

Answer 28

Simple Network Management Protocol UDP 161 Provides collection and organization of information about managed devices on IP networks. Can manage settings of devices. Gather statistics from network devices v1 - The original structured tables, in the clear v2 - A good step ahead, Data type enhancements, bulk transfers, still in the clear. v3 - The new standard, Message encryption, authentication, encryption

Question 29

Describe TFTP

Answer 29

Trivial File Transfer Protocol UDP 69 Very simple file transfer application, read files/write files, transmits files in both directions using applications. No authentication - Not used on production systems

Question 30

Describe RDP

Answer 30

Remote Desktop Protocol Share a desktop from a remote location over network using a GUI. TCP 3389 Remote Desktop Services on many Windows versions Can connect to an entire desktop or just an application Clients for Windows, macOS, Linux, iPhone, and others

Question 31

Describe NTP

Answer 31

Network Time Protocol UDP 123 Switches, routers, firewalls, servers, workstations all have their own clock. Synchronizing the clocks becomes critical for log files, authentification information, outage details. Automatic updates (No flashing 12:00 lights) Flexible - you control how clocks are updated. Very accurate - better than 1 millisecond

Question 32

Describe SIP

Answer 32

Session Initiation Protocol TCP 5060-5061 Voice over IP (VoIP) signaling, Video calls, Instant Messaging Setup and manage VoIP sessions (call, ring, hang-up) Extend voice communication (video conferencing, instant messaging, file transfer)

Question 33

Describe SMB

Answer 33

Server Message Block TCP 445 Protocol used by Microsoft Windows for file sharing, printer sharing. Also called CIFS (Common Internet File System)

Question 34

Describe POP3

Answer 34

Post Office Protocol version 3 TCP 110 Basic mail transfer functionality Receives emails from an email server, authenticate and transfer

Question 35

Describe IMAP4

Answer 35

Internet Message Access Protocol version 4 TCP 143 Allows email clients to receive mail from a remote system, and you can change the status in the remote server. Keeps everything synced. Manage email inbox from multiple clients

Question 36

Describe LDAP

Answer 36

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

Question 37

Describe LDAPS

Answer 37

Lightweight Directory Access Protocol Secure TCP 636 A non-standard implementation of LDAP over SSL

Question 38

Describe H.323

Answer 38

Voice over IP (VoIP) signaling TCP 1720 ITU Telecommunication H32x protocol seriies Setup and manage VoIP sessions One of the earliest VoIP standards, still used today.

Question 39

Describe NetBIOS

Answer 39

NetBIOS TCP 139 UDP 137 Network Basic Input/Output System. Provides services allowing applications on separate computers to communicate over a LAN for file and printer sharing.

Question 40

The _________________ command allows you to see every open port on a specific IP address.

Answer 40

nmap or zenmap