Unit 2: Configuring DNS Servers

DNS Client

A computer making a DNS query.

Domain Name System (DNS)

A distributed hierarchical database composed mainly of computer name and IP address pairs.

Forwarder

A DNS server to which other DNS servers send requests they can't resolve themselves.

Caching-Only DNS Server

A DNS server with no zones. Its sole job is to field DNS queries, do recursive lookups to root servers, or send requests to forwarders and then cache the results.

Reverse Lookup Zone (RLZ)

A DNS zone containing PTR records that map IP addresses to names; it's named with the IP network address (IPv4 or IPv6) of the computer whose records it contains.

Secondary Zone

A DNS zone containing a read-only copy of all resource records for the zone. Changes can't be made directly on a secondary DNS server, but because it contains an exact copy of the primary zone, it's considered authoritative for the zone.

Stub Zone

A DNS zone containing a read-only copy of only the zone's SOA and NS records and the necessary A records to resolve NS records. A stub zone forwards queries to a primary DNS server for that zone and is not authoritative for the zone.

Primary Zone

A DNS zone containing a read/write master copy of all resource records for the zone; this zone is authoritative for the zone.

Forward Lookup Zone (FLZ)

A DNS zone containing records that translate names to IP addresses, such as A, AAAA, and MX records. It's named after the domain whose resource records it contains.

Referral

(1) A response to an iterative query in which the address of another name server is returned to the requester. (2) A prioritized list of servers used to access files in a namespace.

Root Server

A DNS server that keeps a database of addresses of other DNS servers managing top-level domain names.

Top-Level Domain (TLD) Server

A DNS server that maintains addresses of other DNS servers that are authoritative for second-level domains.

Dynamic DNS (DDNS)

A DNS name-registering process whereby computers in the domain can register or update their own DNS records.

Authoritative Server

A DNS server that holds a complete copy of a zone's resource records (typically a primary or secondary zone).

Conditional Forwarder

A DNS server to which other DNS servers send requests targeted for a specific domain.

Global Names Zone (GNZ)

A feature that provides a way for IT administrators to add single-label names (computer names that don't use a domain suffix, such as NetBIOS names) to DNS, thereby allowing client computers to resolve these names without including a DNS suffix in the query.

Zone

A grouping of DNS information that represents one or more domains and possibly subdomains.

Root Hints

A list of name servers preconfigured on Windows DNS servers that point to Internet root servers, which are DNS servers located on the Internet and managed by IANA.

Round Robin

A method of responding to DNS queries when more than one IP address exists for the queried host. Each IP address is placed first in the list of returned addresses an equal number of times so that hosts are accessed alternately

Recursive Query

A query in which the DNS server processes the query until it responds with an address that satisfies the query or with an "I don't know" message. The process might require the DNS server to query several additional DNS servers.

CNAME Record

A record containing an alias for another record that enables you to refer to the same resource with different names yet maintain only one host record.

Host Record

A resource record in a DNS zone that consists of a hostname and an IP address. Also called an A record or AAAA record depending on whether the IP address is IPv4 or IPv6.

A Record

A resource record in a DNS zone that consists of a hostname and an IPv4 address.

AAAA Record

A resource record in a DNS zone that consists of a hostname and an IPv6 address.

Iterative Query

A type of DNS query to which a DNS server responds with the best information it has to satisfy the query. The DNS server doesn't query additional DNS servers in an attempt to resolve the query.

MX Record

A type of DNS resource record that is used to resolve a domain name in an email address to the IP address of a mail server for that domain.

PTR Record

A type of DNS resource record that is used to resolve a known IP address to a hostname.

Glue A Record

An A record used to resolve the name in an NS record to its IP address.

Hostname

An assigned name that is associated with an IP address, so when a client looks up the name www.microsoft.com, the DNS server returns an IP address

DNS Audit Event

An audit event that tracks changes to a DNS server, such as when zone or resource changes are made, and is enabled by default.

DNS Analytic Event

An event that is created every time DNS sends and receives information.

Zone Transfer

An operation that copies all or part of a zone from one DNS server to another and occurs as a result of a secondary server requesting the transfer from another server.

Resource Records

Data in a DNS database containing information about network resources, such as hostnames, other DNS servers, and services; each record is identified by a letter code.

DNS Namespace

The entire DNS tree that defines the structure of the names used to identify resources in network domains. It consists of a root name (defined as a period), top-level domains, second-level domains, optionally one or more subdomains, and hostnames separated by periods.

Fully Qualified Domain name (FQDN)

The full domain name for a host that specifically identifies it within the hierarchy of the Domain Name System.