In a Dns Zone, What Type of Record Holds the Name-to-address Mapping for Ipv6 Addresses?

What is a DNS Zone?

A DNS zone is a singled-out role of the domain namespace which is delegated to a legal entity—a person, organization or company, who are responsible for maintaining the DNS zone. A DNS zone is also an administrative part, allowing for granular control of DNS components, such as authoritative name servers.

When a web browser or other network device needs to find the IP address for a hostname such as "example.com", information technology performs a DNS lookup - essentially a DNS zone cheque - and is taken to the DNS server that manages the DNS zone for that hostname. This server is called the administrative name server for the domain. The authoritative name server and then resolves the DNS lookup past providing the IP accost, or other data, for the requested hostname.

DNS Zone Levels

The Domain Proper name System (DNS) defines a domain namespace, which specifies Top Level Domains (such as ".com"), 2nd-level domains, (such as "acme.com") and lower-level domains, as well called subdomains (such every bit "back up.acme.com"). Each of these levels can be a DNS zone.

For case, the root domain "acme.com" may exist delegated to a Tiptop Corporation. Tiptop assumes responsibility for setting upwards an authoritative DNS server that holds the right DNS records for the domain.

At each hierarchical level of the DNS system, in that location is a Name Server containing a zone file, which holds the trusted, correct DNS records for that zone.

DNS Root Zone

The root of the DNS system, represented by a dot at the end of the domain proper noun—for example, www.example.com.—is the master DNS zone. Since 2016, the root zone is overseen by the Internet Corporation for Assigned Names and Numbers (ICANN), which delegates management to a subsidiary acting every bit the Internet Assigned Numbers Authority (IANA).

The DNS root zone is operated past 13 logical servers, run past organizations similar Verisign, the U.Due south. Army Research Labs and NASA. Any recursive DNS query (learn more than nearly DNS query types) starts past contacting one of these root servers, and requesting details for the next level downwards the tree—the Top Level Domain (TLD) server.

TLD Zones

There is a DNS zone for each Top Level Domain, such equally ".com", ".org" or land codes like ".co.britain". at that place are currently over 1500 top level domains. Most summit level domains are managed by ICANN/IANA.

Domain Zones

Second-level domains like the domain you are viewing now, "ns1.com", are defined every bit separate DNS zones, operated by individuals or organizations. Organizations can run their own DNS name servers, or delegate direction to an external provider.

If a domain has subdomains, they can be office of the aforementioned zone. Alternatively, if a subdomain is an independent website, and requires divide DNS management, information technology can exist defined as its own DNS zone. In the diagram above, "blog.example.com" was setup every bit a DNS zone, whereas "support.example.com" is function of the "case.com" DNS zone.

Secondary DNS Zones

DNS servers tin be deployed in a master/secondary topology, where a secondary DNS server holds a read-only copy of the main DNS server's DNS records. The master server holds the primary zone file, and the secondary server constitutes an identical secondary zone; DNS requests are distributed between primary and secondary servers. A DNS zone transfer occurs when the primary server zone file is copied, in whole or in part, to the secondary DNS server.

All About the DNS Zone File

DNS zone files are defined in RFC 1035 and RFC 1034. A zone file contains mappings between domain names, IP addresses and other resources, organized in the form of resource records (RR).

To meet the bodily zone file for a domain, and test DNS zone transfers, you can perform a zone file lookup using one of many DNS tools.

DNS Zone Types

There are two types of zone files:

A DNS Primary File which authoritatively describes a zone
A DNS Enshroud File which lists the contents of a DNS enshroud—this is but a copy of the authoritative DNS zone

DNS Zone Records

In a zone file, each line represents a DNS resource record (RR). A tape is fabricated upwardly of the following fields:

proper noun

ttl

tape class

record type

record data

Name is an alphanumeric identifier of the DNS tape. It can be left blank, and inherits its value from the previous record.
TTL (time to live) specifies how long the record should exist kept in the local cache of a DNS client. If not specified, the global TTL value at the top of the zone file is used.
Record course indicates the namespace—typically IN, which is the Internet namespace.
Record type is the DNS tape type—for example an A tape maps a hostname to an IPv4 address, and a CNAME is an alias which points a hostname to another hostname.
Record data has one or more than information elements, depending on the tape type, separated by a white space. For case an MX tape has two elements—a priority and a domain proper noun for an electronic mail server.

Zone File Structure

DNS Zone files start with two mandatory records:

Global Time to Live (TTL), which specifies for how records should exist kept in local DNS enshroud.
Start of Authority (SOA) record—specifies the primary administrative name server for the DNS Zone.

Subsequently these two records, the zone file can contain whatsoever number of resource records, which can include:

Name Server records (NS)—specifies that a specific DNS Zone, such as "case.com" is delegated to a specific administrative name server
IPv4 Address Mapping records (A)—a hostname and its IPv4 address.
IPv6 Address records (AAAA)—a hostname and its IPv6 address.
Canonical Name records (CNAME)—points a hostname to an alias. This is another hostname, which the DNS client is redirected to
Post exchanger record (MX)—specifies an SMTP email server for the domain.

Zone File Tips

When adding a record for a hostname, the hostname must end with a period (.)
Hostnames which practise not end with a period are considered relative to the main domain name—for example, when specifying a "www" or "ftp" tape, there is no need for a period.
You tin add comments in a zone file by adding a semicolon (;) after a resource tape.

DNS Zone File Case

$ORIGIN case.com. ; start of the zone file$TTL 30m ; default cache expiration time for resource recordsexample.com. IN SOA ns.example.com. root.example.com. ( 1999120701 ; serial number of this zone file1d ; frequency to refresh secondary DNS (d=solar day)1d ; frequency to refresh secondary DNS in instance of problem4w ; secondary DNS expiration time (w=calendar week)1h ; minimum caching time if resolution failedexample.com. NS dns1.dnsprovider.com. ; in that location are two name server that can provide DNS services for instance.comexample.com. NS dns2.dnsprovider.com.example.com. MX 10 mx1.dnsprovider.com ; mail serverexample.com. MX ten mx2.dnsprovider.comexample.com. A 192.168.100.ane ; IP address for root domain www A 192.168.100.1 ; IP address for www subdomain

DNS Zones and Next-Generation DNS Services

Traditional DNS infrastructure has its limitations. In one case upon a fourth dimension, an IP address pointed to a unmarried server. Now, i IP address can hibernate a pool of load balanced network resource, deployed on dissimilar data centers across the globe. To serve these resources efficiently to users, ensure high operation and allow quick propagation of changes, you should consider a next generation DNS provide similar NS1.

NS1 provides:

Managed DNS - a DNS service powered by a high performance, anycast global DNS network, with avant-garde traffic management features.
Dedicated DNS - fully managed DNS deployment, on premise or in the cloud, with advanced signal-and-click traffic management

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Source: https://ns1.com/resources/dns-zones-explained