Section 2.1 TCP / UDP Ports and Protocols

Which protocol uses TCP ports 20 and 21?

FTP (File Transfer Protocol)

What is the purpose of FTP?

To transfer files between systems

Which protocol uses TCP port 22?

SSH (Secure Shell)

What is the function of SSH?

Secure remote login and command execution

Which protocol uses TCP port 23?

Telnet

Why is Telnet considered insecure?

Transmits data, including passwords, in plaintext

Which protocol uses TCP port 25?

SMTP (Simple Mail Transfer Protocol)

What is SMTP used for?

Sending email between servers

Which protocol uses UDP and TCP port 53?

DNS (Domain Name System)

What does DNS do?

Resolves domain names to IP addresses

Which ports does DHCP use?

UDP ports 67 and 68

What does DHCP do?

Automatically assigns IP addresses to devices

Which protocol uses TCP port 80?

HTTP (Hypertext Transfer Protocol)

What is HTTP used for?

Unsecured web browsing

Which protocol uses TCP port 110?

POP3 (Post Office Protocol 3)

What does POP3 do?

Downloads email from server to local client

Which ports are used by NetBIOS/NetBT?

TCP/UDP 137, 138, and 139

What is NetBIOS used for?

Legacy local network communication

Which protocol uses TCP port 143?

IMAP (Internet Message Access Protocol)

What does IMAP do?

Accesses and manages email on the server

Which ports does SNMP use?

UDP ports 161 and 162

What is SNMP used for?

Monitoring and managing network devices

Which protocol uses TCP and UDP port 389?

LDAP (Lightweight Directory Access Protocol)

What does LDAP do?

Accesses and maintains directory information

Which port does HTTPS use?

TCP port 443

What is HTTPS used for?

Secure web browsing using SSL/TLS

Which protocol uses TCP port 445?

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

What does SMB do?

Provides shared access to files and printers

Which port does RDP use?

TCP port 3389

What is RDP used for?

Remote desktop access to another computer

Which protocol is connectionless and uses UDP?

TFTP (Trivial File Transfer Protocol)

What does TFTP do?

Transfers files without authentication or encryption

Which connectionless protocol assigns IP addresses?

DHCP

What distinguishes UDP from TCP?

UDP is connectionless, TCP is connection-oriented

Which type of protocol does not guarantee delivery?

UDP

Which protocol guarantees delivery using acknowledgments?

TCP

Is DNS typically TCP, UDP, or both?

Both (UDP for queries, TCP for zone transfers)

What kind of communication does SSH use?

Encrypted, connection-oriented

What kind of communication does HTTP use?

Plaintext, connection-oriented

What kind of communication does DHCP use?

Connectionless (UDP)

What is a key feature of TCP?

Reliable delivery through error checking and retransmission

What is a key feature of UDP?

Low latency and minimal overhead

Which protocol is used for real-time services like VoIP?

UDP

What kind of protocol is HTTPS?

TCP-based, connection-oriented

Which protocol should not be used on public networks due to lack of encryption?

Telnet

Which protocol allows browsing shared folders on a Windows network?

SMB

Which mail protocol stores messages on the server?

IMAP

Which mail protocol typically deletes messages from the server after download?

POP3

What protocol is commonly used for remote administration of routers and switches?

SSH

Which protocol uses port 162 for alerts?

SNMP (Simple Network Management Protocol)

Which protocol is used to download configuration files to network devices?

TFTP