A First Hop Redundancy Protocol (FHRP) is a protocol that lets multiple routers share a virtual gateway address so hosts keep connectivity if one router fails. HSRP, VRRP, and GLBP are the common examples CCNA expects you to recognise.
OSPF (Open Shortest Path First) is a link-state interior gateway routing protocol that builds a topology map and computes shortest paths by cost.
A VLAN (Virtual Local Area Network) is a logical segmentation of a switched network that groups ports independently of physical location.
Trunking is the practice of carrying traffic for multiple VLANs over a single switch link using 802.
The Spanning Tree Protocol (STP) is a Layer 2 protocol that prevents switching loops by electing a root bridge and blocking redundant paths.
EtherChannel is a technology that bundles several physical switch links into one logical link for greater bandwidth and redundancy.
Subnetting is the practice of dividing an IPv4 network into smaller subnetworks using a subnet mask or CIDR prefix.
Private IPv4 addressing is the use of the RFC 1918 ranges (10.
NAT (Network Address Translation) is a technique that maps private IP addresses to public addresses at a router boundary.
A First Hop Redundancy Protocol (FHRP) is a protocol that lets multiple routers share a virtual gateway address so hosts keep connectivity if one router fails.
An access control list (ACL) is an ordered set of permit and deny rules a router or switch uses to filter traffic.
AAA (authentication, authorization, and accounting) is a security framework that verifies identity, controls what a user may do, and records activity.
A REST API is a web interface that uses HTTP verbs (GET, POST, PUT, DELETE) to perform CRUD operations on resources, commonly exchanging JSON data.
JSON (JavaScript Object Notation) is a lightweight, human-readable data format that represents data as key-value pairs, arrays, and nested objects.