What Is the Network+? Glossary & Key Terms
- STP
- Spanning Tree Protocol; prevents Layer 2 loops in redundant switched networks by blocking selected redundant paths.
- CIDR
- Classless Inter-Domain Routing; a method of allocating IP addresses and specifying subnet masks using slash notation, such as /24.
- OSI Model
- A seven-layer conceptual framework describing how data moves through a network, from physical transmission up to application-level communication.
- TCP/IP Model
- A four-layer practical networking model (Network Interface, Internet, Transport, Application) that underlies real-world internet communication.
- DHCP
- Dynamic Host Configuration Protocol; automatically assigns IP addresses and other network configuration information to devices on a network.
- DNS
- Domain Name System; translates human-readable domain names into IP addresses that devices use to locate each other on a network.
- NAT
- Network Address Translation; translates private internal IP addresses to a public IP address so internal devices can communicate on the internet.
- VLAN
- Virtual Local Area Network; a logical segmentation of a physical network into separate broadcast domains for security and traffic management.
- QoS
- Quality of Service; a set of techniques that prioritize specific network traffic types to improve performance for latency-sensitive applications.
- VPN
- Virtual Private Network; an encrypted tunnel that allows secure remote access to a private network over an untrusted public network.
- MTTR
- Mean Time to Repair; the average time required to fix a failed system or component and restore it to operation.
- MTBF
- Mean Time Between Failures; the average operating time a system runs before experiencing a failure.
- Demarc
- Demarcation point; the boundary where a telecommunications carrier's network ends and the customer's on-premises wiring begins.
- Single-mode Fiber
- A fiber-optic cable type with a narrow core that uses laser light to transmit signals over long distances with minimal loss.
- Multimode Fiber
- A fiber-optic cable type with a wider core that uses LED light sources, typically suited for shorter-distance connections.
- 802.1Q
- The IEEE standard that defines VLAN tagging on Ethernet frames, allowing switches to identify VLAN membership across trunk links.
- Default Gateway
- The router interface a device uses to send traffic destined for networks outside its own local subnet.
- Subnet Mask
- A value that divides an IP address into its network and host portions, defining the boundaries of a local network segment.
- Stateful Firewall
- A firewall that tracks the state of active network connections and automatically permits legitimate return traffic for those sessions.
- DORA Process
- The four-step sequence a client uses to obtain an IP address from a DHCP server: Discover, Offer, Request, Acknowledge.
- Broadcast Domain
- A logical network segment in which a broadcast frame sent by one device is received by all other devices on that segment.
- Trunk Port
- A switch port configured to carry traffic for multiple VLANs simultaneously, typically using 802.1Q tagging between switches.