Computer Networks

LDAP (Lightweight Directory Access Protocol) is an open, vendor-neutral industry standard for accessing and maintaining distributed directory information services, using TCP port 389.

POP3 (Post Office Protocol version 3) is a standard mail protocol used to receive emails from a remote server to a local client. It operates over TCP port 110.

While standard DNS queries use UDP port 53, DNS zone transfers require a reliable connection to ensure data integrity, so they use TCP port 53.

Kerberos is a network authentication protocol designed to provide strong authentication for client/server applications by using secret-key cryptography. It uses TCP port 88.

FTPS (FTP over SSL/TLS) adds support for the Transport Layer Security and the Secure Sockets Layer cryptographic protocols. It uses ports 989 and 990.

SCP uses SSH for secure file transfer, which operates on TCP port 22. SMTP uses port 25, SNMP uses UDP 161, and RADIUS uses UDP 1812.

SMTP uses TCP port 25 for email transmission between mail servers. FTP uses port 20, Kerberos uses UDP 88, and TFTP uses UDP 69.

A data packet typically contains a header (with source and destination addresses), a payload (the actual data), and a trailer (with error control bits). Route instructions are determined by routers, not stored inside the packet itself.

The Internet and modern networking rely on packet switching, where data is broken into small packets that travel independently across the network.

VoIP (Voice over IP) uses IP addresses to route data packets to the correct destination on a network, just like other internet traffic.

IEEE 802.1x is the standard for port-based network access control, which provides authentication between a device and a RADIUS server. While EAP is used within 802.1x, 802.1x is the framework for the connection.

EAP (Extensible Authentication Protocol) is an authentication framework that provides transport for various authentication methods between a client and an authenticator, such as a RADIUS server.

QoS (Quality of Service) is a set of technologies used to manage network traffic and prioritize specific types of data, such as voice, to ensure clear communication. PAT, DNS, and SIP serve different networking functions.

A bridge operates at the Data Link layer (Layer 2) of the OSI model, where it makes forwarding decisions based on MAC addresses.

Telnet is a legacy protocol that uses port 23 by default for remote terminal access.