Protocols & Ports (Memorize)

Question 1

FTP

Answer 1

FTP

• Active mode: TCP port 21 for control, TCP port 20 for data
• Passive mode: TCP port 21 for control, random TCP port for data
• Best to disable passive mode - random port blocked by fwall

Question 2

TFTP

Answer 2

Trivial FTP

• UDP port 69
• Commonly disabled

Question 3

SSH

Answer 3

SSH

TCP port 22

Question 4

IPSec

Answer 4

IPSec
Encrypts IP traffic - tunnel mode to protect VPN
-Authentication Header (AH) - protocol ID 51
-Encapsulating Security Payload (ESP) - protocol ID 50
-Internet Key Exchange (IKE) - UDP port 500

Question 5

SFTP

Answer 5

SFTP
Secure FTP
-TCP port 22
-Extension of SSH

Question 6

FTPS

Answer 6

FTPS
FTP Secure
-TCP port 989 and 990 or TCP port 20 & 21
-TLS to encrypt FTP

Question 7

SMTP

Answer 7

Simple Mail Transfer Protocol

• TCP port 25
• Use STARTTLS on same port

Question 8

POP3

Answer 8

POP3

TCP port 110

Question 9

Secure POP3

Answer 9

Secure POP3

• port 110 (use STARTTLS)
• Encrypts with SSL or TLS

Question 10

IMAP4

Answer 10

IMAP4
Internet Message Access Protocol
-Store mail on server with folders
-TCP port 143

Question 11

Secure IMAP

-What does it encrypt?

Answer 11

Secure IMAP
Secure Internet Message Access  Protocol
-SSL or TLS
-TCP port 143 (use STARTTLS)
-Encrypts communication downloaded from email server
-No security for outgoing email messages

Question 12

HTTPS

Answer 12

HTTPS
SSL or TLS
-TCP port 443

Question 13

Kerberos

Answer 13

Kerberos

• Authentication protocol in Windows, some Unix
• UDP port 88
• Key Distribution Center (KDC) to issue timestamped tickets

Question 14

LDAP

Answer 14

LDAP
Lightweight Directory Access Protocol
-TCP port 389
-Syntax for object identification and management
-Query X.500 directory (attribute=value)
-Microsoft Active Directory can support LDAP authentication

Question 15

LDAPS

Answer 15

LDAPS
Lightweight Directory Access Protocol Secure
-TCP port 636
-encrypts with TLS
-Syntax for object identification and management

Question 16

RDP

Answer 16

RDP
Remote Desktop Protocol
-TCP port 3389
-UDP port 3389

Question 17

DNS

• Client request
• Zone transfer
• tools to test

Answer 17

DNS

• A records - IPv4
• AAAA records - IPv6
• Zone transfer - TCP port 53
• DNS client queries - UDP port 53
• DNSSEC - helps prevent DNS poisoning; validation of DNS responses; records have digital signatures for integrity
• nslookup (win) & dig (linux) - command s to test DNS

Question 18

Protocols that use TLS to provide secure communications

Answer 18

Protocols that use TLS to provide secure communications

• HTTPS
• FTPS

Question 19

S/MIME

-What does it do

Answer 19

S/MIME

• Public key encryption and digital signatures for email
• Encrypts all email from client to client

Question 20

NTP

Answer 20

NTP

• UDP
• 123

Question 21

SCP

Answer 21

SCP

22

Question 22

telnet

Answer 22

telnet

23

Question 23

SNMP

Answer 23

SNMP
UDP
161

Question 24

RADIUS

Answer 24

RADIUS
UDP
1812
1813

Question 25

TACAS+

Answer 25

TACAS+
TCP
49

Question 26

IPP

Answer 26

IPP
Internet Printing Protocol
-TCP
-631

Question 27

SSTP

Answer 27

SSTP
Secure Socket Tunneling Protocol
-Encrypts VPN traffic over port 443