Port Numbers

Question 1

RDP - Remote Desktop Protocol
port number

Answer 1

3389

RDP uses port 3389, and at each end the firewall must be adjusted to allow access through that port.

Question 2

SSH (secure shell) port number

Answer 2

22

INFO: connection-oriented protocol used to set up secure Telnet connections for remote logins. SSH is secure and runs on port 22

Question 3

File Transfer Protocol (FTP)

Answer 3

PORT NUMBER: 20, 21

INFO: used to manipulate files. FTP can copy files, list and manipulate directories, and view file contents. Port 21 is mainly used for file management and port 20 is used for data transfer. FTP is not secure and transmits in plain text.

Question 4

Telnet

Answer 4

PORT NUMBER: 23

INFO: terminal emulation program that allows for remote access to text on another computer. Telnet is not secure and transmits plaintext.

Question 5

Simple Mail Transfer Protocol (SMTP)

Answer 5

PORT NUMBER: 25.

INFO: used to send email only; a push protocol

Question 6

DNS (Domain Name System)

Answer 6

PORT NUMBER: 53

INFO: used to resolve host names to IP addresses.

Question 7

DHCP (Dynamic Host Configuration Protocol)

Answer 7

PORT NUMBER: 67/68

INFO: assigns IP addresses dynamically to network clients.

Port 67 - server.
Port 68 - client.

Question 8

HTTP - Hypertext Transfer Protocol

Answer 8

PORT NUMBER: 80

INFO: manages connections between web server and client to view internet content

NOT secure and transmits in plain text.

Question 9

POP3 - Post Office Protocol 3

Answer 9

used for downloading email

uses PORT NUMBER 110.

Question 10

Network Basic Input/Output System (NetBIOS)/NetBIOS over TCP/IP (NetBT)

Answer 10

Network Basic Input/Output System (NetBIOS) is an API for communication between computers over a network. NetBIOS works over OSI layer 4 and needs to work with a layer 5 protocol, namely TCP/IP, to function properly. NetBIOS over TCP/IP is called NetBT.

NetBIOS runs on ports 137 AND 139.

Question 11

IMAP (Internet Message Access Protocol)

Answer 11

used for downloading email; currently in 4th version (IMAP 4).

runs on PORT NUMBER 143.

Question 12

SNMP (Simple Network Management Protocol)

Answer 12

used for network management.

Uses PORT NUMBERS 161 for sending and receiving requests and PORT 162 for receiving transmissions from managed devices.

Question 13

LDAP (Lightweight Directory Access Protocol)

Answer 13

used for accessing information stored in an information directory.

PORT NUMBER: 389.

Question 14

HTTPS (Hypertext Transfer Protocol Secure)

Answer 14

secure version of HTTP

uses PORT NUMBER 443

Question 15

Server Message Block (SMB)/Common Internet File System (CIFS)

Answer 15

Server Message Block (SMB) is primarily a Microsoft protocol used for shared file access. Common Internet File System (CIFS) is an enhanced version of SMB.

SMB/CIFS use port 445.

Question 16

Remote Desktop Protocol (RDP)

Answer 16

allows for remote connection to computers.

uses port 3389.

Question 17

TCP (Transmission Control Protocol) vs. UDP (User Datagram Protocol)

Answer 17

Transmission Control Protocol (TCP) is a connection-oriented protocol used to send and receive data over a network. Before data is sent, a connection is established with the receiving host. It is considered a reliable protocol because the receiving host acknowledges that it received the data. TCP is used in cases where receiving the proper data is more important than speed.

User Datagram Protocol (UDP) is a connectionless protocol. Data is sent without any assurance that the receiving host is actually receiving the data. For that reason, it is considered an unreliable protocol. The advantage of UDP over TCP is that it is faster.

Question 18

What are two connectionless protocols?

Answer 18

DHCP—Dynamic Host Configuration Protocol (DHCP) is used to dynamically assign IP configuration information to clients through a lease and uses UDP as its transport protocol. DHCP runs on port 67/68.

TFTP—Trivial File Transfer Protocol (TFTP) is a faster version of FTP that uses UDP rather than TCP as its transport protocol. TFTP uses port 69.

Question 19

What are two connection oriented protocols?

Answer 19

HTTPS—Hypertext Transfer Protocol Secure (HTTPS) is a connection-oriented protocol that uses TCP as its transport protocol. HTTPS uses port 443.

SSH—Secure Shell (SSH) is a connection-oriented protocol that uses TCP as its transport protocol. SSH uses port 22.