232 terms
Glossary
Short, plain-language definitions for the IP, DNS, email-authentication, machine-protocol and AI-agent terms AdminKit's tools and guides use, each with a one-line definition and a link back to the one tool, guide or product where AdminKit actually uses the term, grouped into the same six clusters as the rest of the site.
Updated
Featured — one term per cluster
An A record is the basic DNS record type that maps a hostname to an IPv4 address, defined in RFC 1035. A domain can publish several for the same name to spread traffic across servers. AdminKit's DNS lookup tool queries a domain's A records alongside AAAA, MX, TXT, NS and CAA in one lookup.
ARC (Authenticated Received Chain) lets each server in an email forwarding chain sign a record of what a message's SPF, DKIM and DMARC results looked like before that hop forwarded it onward. AdminKit's guide explains how ARC preserves authentication results across a forwarding chain that would otherwise fail SPF.
464XLAT, defined in RFC 6877, lets an IPv4-only app keep working on a mobile network that only assigns IPv6 addresses, by combining a device-side translator (CLAT) with a provider-side NAT64 gateway (PLAT). AdminKit's My IP tool shows whether a connection is actually IPv6-only, the condition that makes 464XLAT necessary in the first place.
ACME, defined in RFC 8555, lets a server prove it controls a domain and receive a signed TLS certificate automatically, with no human filling out a CA request form by hand. It's what makes short-lived certificates practical, like Let's Encrypt's 90-day ones. AdminKit's SSL/TLS check can confirm the validity window of a certificate an ACME client like Let's Encrypt issued.
A2A (Agent2Agent Protocol) is an open spec letting independent AI agents, built on different frameworks, discover each other's capabilities via a published Agent Card and delegate tasks between them. It solves a different problem than MCP: MCP connects an agent to tools, A2A connects one agent to another. AdminKit's MCP & Agent Gateway governs the MCP side.
Email authentication
- ARC (Authenticated Received Chain) See how ARC preserves authentication results across a forwarding chain
- ARF (Abuse Reporting Format) See how reputation-based blacklisting compares to the per-message complaint signal ARF/FBL reports provide
- Authentication-Results header This guide explains the SPF, DKIM and DMARC checks this header reports the results of
IP & network
- 464XLAT Compare with CGNAT, AdminKit's guide to IPv4-side address sharing -- 464XLAT solves the mirror-image problem on IPv6-only mobile networks
- Anycast DNS lookup queries Cloudflare's public anycast DoH resolver on your behalf
- ARP (Address Resolution Protocol) Look up the vendor behind a MAC address — the same address ARP resolves for local delivery
Machine protocols
- ACME protocol Check the validity window of a certificate an ACME client like Let's Encrypt issued
- ALPN (Application-Layer Protocol Negotiation) Check the TLS handshake a host completes, the same handshake ALPN negotiation is part of
- BACnet Check whether a building-automation port is reachable from outside
AI agents & MCP
- A2A (Agent2Agent Protocol) See how the AdminKit MCP & Agent Gateway governs which tools an agent can call
- Cancellation (MCP) See how a security gateway for MCP servers logs long-running calls, including the progress and cancellation notifications passing through it
- Completion (MCP) See how AdminKit's MCP gateway sits in the request path every call, including completion requests, passes through
Frequently asked questions
What's free today?
Reading the glossary is free. All 232 entries published so far are short, sourced definitions with no account needed.
Is the glossary complete?
No — it grows as AdminKit's tools and guides introduce new terms. Each entry links back to the one tool, guide or product where AdminKit actually uses the term.
How are terms grouped on this page?
Into the same six clusters as tools and guides. Each section below lists up to 3 terms, with a link to the complete list on that cluster's hub page.