Networking Glossary
Browse 101 networking terms organized by category — from IP addressing and DNS to security and VPN.
IP Addressing (15)
A network addressing method where the same IP address is assigned to multiple servers in …
A network communication method that sends data to all devices on a subnet simultaneously. The …
Classless Inter-Domain Routing. A method of allocating IP addresses using variable-length subnet masking (e.g., 10.0.0.0/8) …
Dynamic Host Configuration Protocol. A network protocol that automatically assigns IP addresses, subnet masks, gateways, …
An IP address that is temporarily assigned to a device by a DHCP server and …
Internet Protocol version 4. The fourth revision of IP using 32-bit addresses (e.g., 192.168.1.1), providing …
Internet Protocol version 6. The successor to IPv4 using 128-bit addresses (e.g., 2001:0db8::1), providing a …
A reserved IP address (127.0.0.1 in IPv4, ::1 in IPv6) that routes traffic back to …
A network communication method that sends data from one source to a specific group of …
Network Address Translation. A method of remapping private IP addresses to a single public IP …
An IP address from reserved ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) used within local networks. Private addresses …
A globally unique IP address assigned by an ISP that is routable on the public …
A permanently assigned IP address that does not change over time. Commonly used for servers, …
A 32-bit number (e.g., 255.255.255.0) that divides an IP address into network and host portions. …
A network communication method that sends data from one sender to one specific receiver. The …
DNS (12)
A DNS record that maps a domain name to an IPv4 address (e.g., example.com -> …
A DNS record that maps a domain name to an IPv6 address. Named "AAAA" (quad-A) …
A DNS server that holds the original, definitive DNS records for a domain zone. It …
A DNS record that creates an alias from one domain name to another (e.g., www.example.com …
Domain Name System. The hierarchical, distributed naming system that translates human-readable domain names (e.g., example.com) …
A server that receives DNS queries from clients and resolves domain names by querying the …
Mail Exchange record. A DNS record that specifies the mail server responsible for receiving email …
Name Server record. A DNS record that delegates a domain or subdomain to a set …
Pointer record. A DNS record used for reverse DNS lookups, mapping an IP address back …
A DNS resolution mode where the server performs the full lookup on behalf of the …
Start of Authority record. A DNS record that contains administrative information about a zone, including …
A DNS record that holds arbitrary text data. Commonly used for email authentication (SPF, DKIM, …
Routing (10)
A large network or group of networks under a single administrative policy, identified by a …
Border Gateway Protocol. The routing protocol that exchanges reachability information between autonomous systems, effectively determining …
A routing table entry (0.0.0.0/0 in IPv4) that matches all destination addresses not covered by …
A network device (typically a router) that serves as the access point from a local …
One segment of a network path between a source and destination, representing the passage of …
Open Shortest Path First. An interior gateway routing protocol that uses link-state advertisements and Dijkstra's …
A network device that forwards data packets between different networks by examining destination IP addresses …
A data structure stored in a router that lists known network destinations and the next …
A network diagnostic tool that maps the path packets take from source to destination by …
A field in an IP packet header that limits the packet's lifespan by specifying the …
Security (15)
A digital document that binds a cryptographic key pair to an organization or domain, enabling …
Distributed Denial of Service. An attack that overwhelms a target server or network with massive …
An attack that corrupts DNS cache entries to redirect domain name lookups to a malicious …
The process of converting plaintext data into ciphertext using a cryptographic algorithm and key, making …
A network security device or software that monitors and filters incoming and outgoing traffic based …
HTTP Secure. The encrypted version of HTTP that uses TLS to protect data in transit …
A security system that monitors network traffic or system activity for suspicious patterns and known …
An attack where an adversary secretly intercepts and potentially alters communication between two parties who …
A technique used to discover which network ports on a host are open and listening …
An intermediary server that forwards requests between a client and destination server. Forward proxies anonymize …
A general-purpose proxy protocol (SOCKS4/SOCKS5) that relays any TCP (and optionally UDP) traffic through a …
Secure Sockets Layer / Transport Layer Security. Cryptographic protocols that provide encrypted, authenticated communication over …
The Onion Router. An anonymity network that routes traffic through multiple encrypted relays (typically three) …
Virtual Private Network. A technology that creates an encrypted tunnel between a device and a …
A security model based on the principle of "never trust, always verify." Every access request …
VPN (8)
A privacy flaw where DNS queries bypass the VPN tunnel and are sent to the …
Internet Protocol Security. A suite of protocols that authenticates and encrypts IP packets at the …
Layer 2 Tunneling Protocol. A VPN tunneling protocol that encapsulates data but provides no encryption …
An open-source VPN protocol that uses SSL/TLS for key exchange and can operate over UDP …
A VPN configuration that routes only selected traffic through the VPN tunnel while allowing other …
An encrypted, encapsulated connection between two endpoints through which all tunneled data passes securely across …
A privacy vulnerability where WebRTC (a browser API for real-time communication) reveals a user's real …
A modern, lightweight VPN protocol that uses state-of-the-art cryptography (ChaCha20, Curve25519) with a minimal codebase …
Protocols (12)
Address Resolution Protocol. A Layer 2 protocol that maps an IP address to a physical …
File Transfer Protocol. A standard protocol for transferring files between a client and server over …
Hypertext Transfer Protocol. The application-layer protocol for transmitting web pages, APIs, and other resources. HTTP …
Internet Control Message Protocol. A network-layer protocol used for diagnostic and error-reporting purposes. Ping (echo …
Internet Message Access Protocol. An email retrieval protocol that synchronizes messages between a server and …
Network Time Protocol. A protocol for synchronizing clocks across computer networks to within milliseconds of …
Post Office Protocol version 3. An email retrieval protocol that downloads messages from a server …
Simple Mail Transfer Protocol. The standard protocol for sending email between servers and from clients …
Simple Network Management Protocol. A protocol for monitoring and managing network devices (routers, switches, servers) …
Secure Shell. A cryptographic protocol for secure remote login, command execution, and file transfer over …
Transmission Control Protocol. A reliable, connection-oriented transport protocol that guarantees ordered, error-checked delivery of data …
User Datagram Protocol. A connectionless transport protocol that sends datagrams without establishing a connection or …
Web (8)
The practice of storing copies of frequently accessed data closer to the requester to reduce …
Content Delivery Network. A geographically distributed network of servers that caches and serves content from …
Cross-Origin Resource Sharing. A browser security mechanism that uses HTTP headers to control which origins …
Three-digit codes returned by a web server indicating the result of a request. Organized into …
A device or service that distributes incoming network traffic across multiple backend servers to ensure …
Representational State Transfer Application Programming Interface. An architectural style for web services that uses standard …
A server that sits in front of backend servers, forwarding client requests and returning responses …
A communication protocol that provides full-duplex, persistent connections between a browser and server over a …
Wireless (5)
A short-range wireless technology for exchanging data between devices over the 2.4 GHz ISM band. …
Media Access Control address. A unique 48-bit hardware identifier (e.g., AA:BB:CC:DD:EE:FF) assigned to a network …
Service Set Identifier. The human-readable name of a Wi-Fi network that access points broadcast so …
A family of wireless networking protocols based on the IEEE 802.11 standards, enabling devices to …
Wi-Fi Protected Access. A family of security protocols (WPA, WPA2, WPA3) that encrypt wireless network …
Monitoring (5)
The maximum data transfer rate of a network link, typically measured in bits per second …
The time delay for a data packet to travel from source to destination, typically measured …
The percentage of data packets that fail to reach their destination, typically caused by network …
A network utility that sends ICMP echo request packets to a target host and measures …
The actual rate of successful data transfer over a network, measured in bits per second. …
General (11)
Autonomous System Number. A unique identifier (e.g., AS13335 for Cloudflare) assigned by a Regional Internet …
An attack or misconfiguration where a network falsely announces ownership of IP prefixes it does …
A physical facility housing networked computer systems, storage, and networking equipment with redundant power, cooling, …
A human-readable address (e.g., example.com) that identifies a website or service on the internet. Domain …
A network configuration where devices and infrastructure simultaneously support both IPv4 and IPv6 protocols. The …
A physical facility where multiple ISPs and networks interconnect to exchange traffic directly rather than …
The process of estimating the geographic location (country, city, coordinates) associated with an IP address …
Internet Service Provider. A company that provides internet access to consumers and businesses, assigning public …
A mutual arrangement between two networks to exchange traffic directly and freely (settlement-free peering) at …
A paid arrangement where one network (the customer) pays another (the transit provider) for access …
A query-and-response protocol for looking up registration information about domain names, IP addresses, and autonomous …