Term 481
Private IP address
A private IP address is a non-internet-routable address used within a local network to identify devices and allow them to communicate with each other without direct exposure to the public internet.
Acronym study
Terms 481–510 of 716 CCNA acronyms and key terms. Each entry includes a plain-English definition and a link to the full 800-word glossary page with exam context and practice questions.
Term 481
A private IP address is a non-internet-routable address used within a local network to identify devices and allow them to communicate with each other without direct exposure to the public internet.
Term 482
Private Link is a technology that lets you connect your virtual network to a service over a private, secure connection inside the cloud provider's infrastructure, instead of going over the public internet.
Term 483
A private subnet is a segmented portion of a cloud or on-premises network that is not directly accessible from the public internet, used to host internal resources securely.
Term 484
AWS PrivateLink is a service that lets you securely access services hosted on AWS VPCs as if they were on your own private network, without exposing traffic to the public internet.
Term 485
Protect mode is a security feature on Cisco switches that prevents a port from learning new MAC addresses once it exceeds a configured limit, but unlike errdisable, it does not shut down the port or generate an SNMP trap.
Term 486
A proxy is an intermediary server that sits between a client and a destination server, forwarding requests and responses while providing security, privacy, and control.
Term 487
A pre-shared key (PSK) is a secret string of characters shared in advance between two parties to authenticate and encrypt wireless or VPN communications.
Term 488
A PTR record is a type of DNS record that maps an IP address to a domain name, essentially performing the reverse of the more common A record.
Term 489
A globally unique IP address assigned to a device that allows it to communicate directly over the internet.
Term 490
A public subnet is a segment of a cloud Virtual Private Cloud (VPC) or traditional network that has a direct route to the internet via an Internet Gateway, allowing resources within it to send and receive traffic from the public internet.
Term 491
A punchdown tool is a handheld device used by network technicians to push wires into insulation-displacement connectors on keystone jacks, patch panels, and punchdown blocks, securing a reliable electrical connection without stripping the insulation.
Term 492
PVST+ (Per-VLAN Spanning Tree Plus) is a Cisco proprietary enhancement of the Spanning Tree Protocol that runs a separate instance of STP for each VLAN, allowing per-VLAN load balancing while maintaining loop-free topology.
Term 493
QoS (Quality of Service) is a network technique that manages data traffic to ensure critical applications get the bandwidth and low latency they need.
Term 494
A Quad Small Form-factor Pluggable (QSFP) is a compact, hot-pluggable transceiver module used in networking to connect switches, routers, and servers to fiber optic or copper cables, supporting four data channels in one module.
Term 495
Quality of Service (QoS) is a set of technologies used to manage network traffic by prioritizing certain types of data to ensure reliable performance for critical applications.
Term 496
Quantum computing is a type of computation that uses quantum bits (qubits) and principles of quantum mechanics to process information in ways that classical computers cannot.
Term 497
Radio Frequency Identification (RFID) is a wireless technology that uses radio waves to automatically identify and track tags attached to objects, people, or animals without requiring direct line-of-sight.
Term 498
RADIUS is a network protocol that provides centralized authentication, authorization, and accounting management for users who connect and use a network service.
Term 499
Rapid PVST+ is a Cisco-proprietary enhancement of the Spanning Tree Protocol that creates a separate spanning tree instance for each VLAN and uses Rapid Spanning Tree Protocol (802.1w) to provide much faster convergence after a network topology change.
Term 500
Rapid Spanning Tree Protocol (RSTP) is a network protocol that prevents loops in Ethernet networks by quickly recalculating the best path when a link fails.
Term 501
Remote Desktop Protocol is a Microsoft protocol that lets you connect to and control another computer over a network as if you were sitting in front of it.
Term 502
A Reachability Analyzer is a tool or feature that tests whether a network path exists between two endpoints, verifying connectivity and identifying potential routing or firewall issues.
Term 503
Received Signal Strength Indicator (RSSI) is a measurement of how strong a wireless signal is when it reaches a receiving device, like a laptop connecting to Wi-Fi.
Term 504
A receiver is a hardware device or software component that accepts incoming signals, data, or transmissions from a sender over a communication channel.
Term 505
A hidden section on a computer's hard drive that contains the files needed to restore the operating system to its factory state.
Term 506
A recursive lookup is a query process where a DNS resolver asks multiple DNS servers one after another until it finds the IP address for a domain name, rather than relying on pre-stored information.
Term 507
Redirection is a mechanism that sends output or input from a command or program to a different destination, such as a file, another command, or a device, instead of the default screen or keyboard.
Term 508
Redundancy is the practice of adding extra components or systems so that if one fails, another can take over without interruption.
Term 509
Regex (regular expression) is a sequence of characters that defines a search pattern, used to match, find, or manipulate text in strings.
Term 510
A regional load balancer distributes incoming network traffic across resources located in multiple geographic regions to ensure high availability, low latency, and fault tolerance at a global scale.