Term 1
/etc/hosts
A local text file on Unix-like operating systems that manually maps hostnames to IP addresses, overriding DNS for specified entries.
Acronym study
Terms 1–30 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 1
A local text file on Unix-like operating systems that manually maps hostnames to IP addresses, overriding DNS for specified entries.
Term 2
/etc/resolv.conf is a configuration file on Linux and Unix-like systems that tells the computer which Domain Name System (DNS) servers to use when converting domain names like google.com into IP addresses.
Term 3
5G is the fifth generation of cellular network technology, designed to deliver faster speeds, lower latency, and support for many more connected devices than previous generations.
Term 4
802.1Q is the networking standard that allows multiple virtual LANs (VLANs) to share a single physical network link by tagging Ethernet frames with VLAN identification information.
Term 5
802.1X is a network access control standard that authenticates devices before they are allowed to connect to a wired or wireless network.
Term 6
An A record is a DNS record that maps a domain name to the IPv4 address of the server hosting that domain.
Term 7
An A record is a type of DNS resource record that maps a domain name to an IPv4 address.
Term 8
AAA (Authentication, Authorization, and Accounting) is a security framework that controls who can access a network, what they are allowed to do, and tracks what they did.
Term 9
An AAAA record is a DNS record that maps a domain name to an IPv6 address, allowing devices to find each other over the internet using the newer IP addressing system.
Term 10
An Area Border Router is an OSPF router that connects multiple OSPF areas, including the backbone area, and exchanges routing information between them.
Term 11
An Access Control List is a set of rules that decides which traffic is allowed or denied entry to a network or device.
Term 12
An access point is a device that creates a wireless local area network, usually by connecting to a wired network and broadcasting a Wi-Fi signal for computers, phones, and tablets to join.
Term 13
An access port is a switch port that connects to a single end device, like a computer or printer, and carries traffic for only one VLAN.
Term 14
An Access Control List is a set of rules that determines who or what can access specific network resources or data.
Term 15
Address Resolution Protocol (ARP) is a network protocol that maps a device's IP address to its physical MAC address so data can travel across a local network.
Term 16
Administrative distance is a number that a router uses to decide which routing protocol's route to trust when it learns about the same destination from multiple different routing protocols.
Term 17
AES is a fast and secure encryption standard used worldwide to protect sensitive data by scrambling it so only authorized parties can read it.
Term 18
AH (Authentication Header) is an IPsec protocol that provides connectionless integrity, data origin authentication, and anti-replay protection for IP packets.
Term 19
AH (Authentication Header) is an IPsec protocol that provides connectionless integrity, data origin authentication, and anti-replay protection for IP packets.
Term 20
Aircrack-ng is a suite of wireless network security tools used to capture packets, monitor networks, and crack WEP and WPA-PSK keys for penetration testing and security auditing.
Term 21
An Alias record is a DNS record type that maps a hostname to another hostname, seamlessly routing traffic to AWS resources like load balancers or CloudFront distributions.
Term 22
Allowed VLANs are the specific VLANs whose traffic is permitted to pass over a specific trunk link between switches, acting as an access control filter for VLAN traffic on a port.
Term 23
An alternate port is a switch port that offers a backup path to the root bridge in a Spanning Tree Protocol network, remaining blocked until the primary path fails.
Term 24
An AP (Access Point) bridges wireless clients to a wired network, acting as a central transceiver and controller for Wi-Fi communications.
Term 25
An API is a set of rules that allows software applications to communicate and exchange data with each other.
Term 26
APIPA is a Windows feature that automatically assigns a private IP address (169.254.x.x) to a device when a DHCP server is unavailable, allowing limited local network communication.
Term 27
An application crash is when a software program stops working unexpectedly and either closes, freezes, or becomes unresponsive.
Term 28
An Application Gateway is a network device or cloud service that manages and secures traffic between users and web applications by applying rules, routing requests, and offloading tasks like SSL encryption.
Term 29
A set of rules and tools that allows one software program to talk to another, like a messenger between applications.
Term 30
An Application Security Group (ASG) is a cloud networking feature that groups virtual machines logically and allows you to apply security rules based on the application workload, rather than individual IP addresses.