A record
An Address record maps a domain name to a 32-bit IPv4 address. It is one of the most common DNS data types and is normally used for forward name resolution.
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311 definitions associated with DNS.
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Page 1 of 13AA flag
The Authoritative Answer bit in a DNS response indicates that the responding server is authoritative for the name in the answer section. It does not mean every item in the response is authoritative, such as some additional-section data.
Read definitionAAAA record
An IPv6 Address record maps a domain name to a 128-bit IPv6 address. The name is pronounced "quad A".
Read definitionAbsolute domain name
A domain name expressed relative to the DNS root, usually shown with a trailing dot, such as host.example.com. The trailing dot prevents a resolver or tool from appending a local search suffix.
Read definitionActive Directory-integrated zone
A Microsoft DNS zone whose data is stored in Active Directory and replicated through AD replication rather than only through DNS zone transfers. It can support secure dynamic updates and multi-writer operation on eligible domain controllers.
Read definitionAddress registration
A mechanism by which a host informs a DHCPv6 infrastructure component about an IPv6 address it configured through another method, such as SLAAC. This can help DDI systems maintain address visibility and DNS registration.
Read definitionAging
A Microsoft DNS mechanism that timestamps eligible dynamically registered records so old data can later be removed by scavenging. Static records normally do not age unless explicitly converted or timestamped.
Read definitionAlias
A name that points to another canonical name or target. CNAME is the standardized alias record for most owner names, while provider-specific ALIAS or ANAME features often synthesize A and AAAA answers at a zone apex.
Read definitionALIAS record
A non-standard provider feature that allows an alias-like configuration where a CNAME is not allowed, often at the zone apex. The authoritative platform follows the target and returns synthesized address records.
Read definitionAllow-query
A policy controlling which clients may ask a DNS server questions. It is commonly enforced globally, per view, or per zone.
Read definitionAllow-recursion
A policy controlling which clients may use a resolver to perform recursive resolution. Restricting recursion prevents an internal resolver from becoming an open resolver.
Read definitionAllow-transfer
A policy controlling which systems may request AXFR or IXFR zone transfers. Transfers should normally be limited to designated secondaries and management systems.
Read definitionANAME record
A proposed or vendor-specific alias-at-apex mechanism that lets an operator point a name to another name while serving address records to clients. It is not a universally standardized DNS resource record type.
Read definitionANY query
A DNS query using QTYPE 255 that asks for whatever records a server chooses to return for a name. It does not reliably mean "all records" and modern servers often minimize or synthesize the response to reduce abuse.
Read definitionAnycast
A routing design in which multiple nodes advertise the same service IP address and the network directs a client to a reachable instance, often the topologically closest one. Anycast is widely used for authoritative and recursive DNS resilience.
Read definitionApex
The top name of a DNS zone. It is also called the zone apex and contains the zone's SOA and authoritative NS record sets.
Read definitionAuthoritative answer
A response based on data for which the responding server is authoritative, rather than solely on recursive cache content. The AA bit normally identifies authoritative responses.
Read definitionAuthoritative data
DNS data served from an authoritative zone or a properly configured authoritative data source. Cached copies at resolvers are not authoritative data even when they reproduce the same record set.
Read definitionAuthoritative server
A DNS server that provides authoritative answers for one or more zones. It may obtain data from a primary source, a zone transfer, a database, a catalog, or a hosted control plane.
Read definitionAuthoritative-only server
A server configured to answer only from its authoritative zones and not to provide recursion to clients. Public authoritative infrastructure should normally use this model.
Read definitionAXFR
A full zone transfer that sends the complete contents of a zone from one authoritative server to another authorized system. Large or sensitive transfers should be protected by ACLs, TSIG, and secure transport where supported.
Read definitionBailiwick
The domain namespace for which a server is considered authoritative in a particular delegation context. Resolvers use bailiwick rules to decide which additional data, especially glue, can be safely cached.
Read definitionBase domain
An informal term that may mean the registrable domain, organizational domain, or zone apex depending on context. Because it is ambiguous, documentation should state the intended meaning.
Read definitionBIND
Berkeley Internet Name Domain, a widely used open-source DNS server and tool suite maintained by ISC. Its configuration vocabulary influences many general DNS terms, even when another platform is used.
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