Term 61
BPDU
A Bridge Protocol Data Unit is a layer 2 frame that switches use to exchange information about the Spanning Tree Protocol (STP) to prevent network loops.
Acronym study
Terms 61–90 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 61
A Bridge Protocol Data Unit is a layer 2 frame that switches use to exchange information about the Spanning Tree Protocol (STP) to prevent network loops.
Term 62
BPDU Guard is a Cisco switch feature that protects the network from unauthorized devices by disabling a port if it receives a Bridge Protocol Data Unit (BPDU).
Term 63
The Bridge ID is an 8-byte value used in Spanning Tree Protocol to uniquely identify each bridge or switch in a network and determine the root bridge of the spanning tree topology.
Term 64
Bridge priority is a numerical value used in Spanning Tree Protocol to determine which switch becomes the root bridge in a network.
Term 65
A Bridge Protocol Data Unit (BPDU) is a special message that network switches exchange to detect and prevent loops in an Ethernet network.
Term 66
Broadband is a high-speed internet connection that can carry multiple data signals at once, like having a wide highway for all your online traffic.
Term 67
A broadcast address is a special network address used to send data to every device on a local network segment simultaneously.
Term 68
A broadcast domain is a network segment where any device can send a broadcast message that all other devices on that segment will receive and process.
Term 69
A broadcast network is a type of communication network where a single message sent from one device is received by all other devices connected to the same network segment.
Term 70
Broadcast OSPF is a mode of OSPF operation used on multi-access broadcast networks (like Ethernet) where routers automatically discover neighbors and elect a Designated Router to reduce routing update traffic.
Term 71
A browser redirect is when a web browser automatically sends a user from one web address to a different one, often without the user clicking anything, which can be caused by legitimate server instructions, malware, or network interference.
Term 72
A Blue Screen of Death (BSOD) is a stop error screen displayed by Windows when a critical system error forces the operating system to shut down to prevent damage.
Term 73
A BSSID is the MAC address of an access point's radio interface, uniquely identifying a wireless cell in a WLAN.
Term 74
Cable internet is a type of broadband internet access that uses the same coaxial copper cables as cable television to deliver high-speed data to homes and businesses.
Term 75
A cable tester is a device used to verify that network or electrical cables are wired correctly and can carry signals without interruption.
Term 76
A CAM table is a memory table inside a network switch that maps each connected device's MAC address to the specific switch port where that device is located.
Term 77
A CAN (Controller Area Network) is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other without a host computer.
Term 78
A DNS record that maps an alias domain name to the official or canonical domain name, like a nickname pointing to a real name.
Term 79
A captive portal is a web page that you must see and interact with before you are allowed full access to a public or guest Wi-Fi network.
Term 80
CAPWAP (Control and Provisioning of Wireless Access Points) is a standard protocol that allows a central controller to manage multiple wireless access points, separating the control plane from the data plane in a wireless network.
Term 81
CDP is a Cisco proprietary protocol used by network devices to share information about themselves with directly connected neighbors, helping network administrators discover and understand the topology.
Term 82
A wide-area network that uses cellular towers and mobile data technology to connect devices to the internet without physical cables.
Term 83
A Certificate Signing Request (CSR) is a specially formatted message sent by an applicant to a Certificate Authority (CA) to request a digital certificate that binds their public key to their identity.
Term 84
A certificate warning is a security alert a web browser or application displays when it cannot fully trust the digital certificate presented by a website or service.
Term 85
The CIA triad is a foundational security model that guides organizations in protecting data through confidentiality, integrity, and availability.
Term 86
CIDR (Classless Inter-Domain Routing) is a method for allocating IP addresses and routing IP packets that replaces the older class-based system, allowing more flexible and efficient use of address space.
Term 87
CIDR notation is a compact way to represent an IP address and its associated network prefix, showing how many bits of the address identify the network versus the host.
Term 88
A proprietary Layer 2 network protocol used by Cisco devices to discover information about directly connected neighbor devices.
Term 89
A centralized network management and automation platform from Cisco that provides intent-based networking for easier configuration, monitoring, and troubleshooting of Cisco devices.
Term 90
Classless Inter-domain Routing (CIDR) is a method for allocating IP addresses and routing IP packets more efficiently by replacing the old class-based system with variable-length subnet masks.