Network Protocols and Port Numbers

Question 1

20/21 TCP
Port 21 is the control port while port 20 is used to
transfer files.

Answer 1

File Transfer Protocol - FTP.

Question 2

22 (TCP/UDP)
Designed to transmit data through a remote
connection. FTP that uses SSH to
encrypt file transfers.

Answer 2

Secure Shell (SSH) / SSH SFTP

Question 3

49
Cisco proprietary remote authentication protocol.

It allows a remote access server to communicate with an authentication server to validate user access onto the network.

More secure than RADIUS however a little slower due to TCP

Answer 3

TACACS+

Question 4

53 TCP/UDP
Associates IP address with domain name

Answer 4

Domain Name System - DNS

Question 5

67/68
Assigns IP addresses to devices on a network. Creates multiple private IP addresses from one public IPV4 address

Answer 5

Dynamic Host Configuration
Protocol (DHCP)

Question 6

80 TCP
Protocol used for websites and most internet traffic (non-secure variant)

Answer 6

HTTP

Question 7

88 TCP/UDP
Protocol that authenticates service requests between two or more trusted hosts across an untrusted network, like the internet. It uses secret-key cryptography and a trusted third party for authenticating client-server applications and verifying users’ identities.

Answer 7

Kerberos

Question 8

110 TCP
Protocol for communicating with an email server. Allows ONE-WAY communication

Answer 8

POP3 (Post Office Protocol)

Question 9

143 / 993 TCP

Protocol for communicating with an email server allowing TWO-WAY communication.

Answer 9

Internet Message Access Protocol (IMAP)

Question 10

161 / 162 UDP

Protocol used to monitor and manage network
devices on IP networks.

Answer 10

Simple Network Management
Protocol (SNMP)

Question 11

443 TCP
Secure version of HTTP. Uses TLS encryption

Answer 11

HTTPS

Question 12

389 TCP/UDP

Used to manage and communicate with directories.

Answer 12

Lightweight Directory Access
Protocol (LDAP)

Question 13

636 TCP/UDP

Secure version of LDAP that uses SSL/TLS for
encryption.

Answer 13

LDAP Secure

Question 14

989 / 990 TCP

FTPS uses TLS for encryption. It can run on ports
20/21 but is sometimes allocated to ports 989/990.

Answer 14

File Transfer Protocol Secure
(FTPS)

Question 15

993 TCP

Secure version of IMAP with SSL/TLS encryption

Answer 15

Internet Message Access
Protocol Secure (IMAPS)

Question 16

1812 / 1813 UDP

protocol that is commonly used to authenticate and authorize (1812) and for accounting (1813)

Answer 16

RADIUS

Question 17

3868
TCP

Developed as an upgrade to RADIUS

Answer 17

Diameter

Question 18

5004

secure protocol used to
stream audio and video communication using UDP. EX: ZOOM

Answer 18

Secure Real Time Protocol
(SRTP)

Question 19

1723 TCP/UDP

Underlying VPN protocol with security

Answer 19

Point to Point Tunneling
Protocol (PPTP)

Question 20

3389 TCP/UDP

Windows proprietary protocol that provides a remote
connection between two computers.

Answer 20

Remote Desktop Protocol (RDP)

Question 21

1433 TCP

Port used to connect to Microsoft SQL server for SQL database queries

Answer 21

MS SQL

Question 22

445 TCP

Protocol used for access to shared files and resources across a network

Answer 22

SMB Sever Message Block

Question 23

5060

signaling protocol used for initiating, maintaining, and terminating communication sessions that include voice, video and messaging applications.

Answer 23

SIP (Session Initiation Protocol)

Question 24

23 (TCP/UDP)

a network protocol that allows a user on one computer to log into another computer that is part of the same network. Inherently not secure - data is not encrypted

Answer 24

Telnet

Question 25

25 TCP Communication between mail servers

Answer 25

SMTP Simple Mail Transfer Protocol

Question 26

69 UDP Simple version of FTP to put a file on a remote host and vice versa

Answer 26

TFTP Trivial File Transfer Protocol

Question 27

119 TCP Used to transfer unsent articles

Answer 27

NNTP Network News Transfer Protocol

Question 28

135 TCP/UDP (Remote procedure call) used to locate DCOM ports to request a service from a program on another computer on the network

Answer 28

RPC/DCOM-scm

Question 29

137/138/139 TCP/UDP Used to conduct name querying, sending of data and other functions over a Net BIOS connection

Answer 29

Net BIOS

Question 30

162 TCP/UDP Used to send TRAP and InformRequests to the SNMP manager on a network

Answer 30

SNMPTRAP

Question 31

465/587 TCP SMTP with SSL/TLS encryption

Answer 31

SMTP Secure

Question 32

514 UDP Used to conduct computer message logging, mainly for routers and firewalls

Answer 32

Syslog

Question 33

860 TCP Used for linking data storage facilities over IP

Answer 33

iSCSI (i-scussi)

Question 34

995 TCP SSL/TLS encrypted version of POP3

Answer 34

POP3 Secure

Question 35

1645/1646 UDP Alternative RADIUS

Answer 35

RADIUS (Alternative)

Question 36

1701 UDP Layer 2 tunnel protocol used as underlying VPN protocol but is not secure - needs to be paired with IPSEC for security

Answer 36

L2TP

Question 37

3225 TCP/UDP Used to encapsulate fiber channel frames within TCP/IP packets

Answer 37

FCIP - Fibre Channel IP

Question 38

3260 TCP Target listening port of iSCSI when linking data storage facilities over IP

Answer 38

iSCSI Target

Question 39

6514 TCP Used to conduct computer message logging, mainly for routers and firewalls over SSL/TLS encryption

Answer 39

Syslog over TLS

Question 40

3306 TCP Classic database port

Answer 40

Classic mySQL