DNS zone

In the Domain Name System of the Internet zone refers to the part of the domain tree for which a name server ( also referred to as NS ) is responsible and therefore knows the official data. A zone is managed by a primary name server. To increase availability in case of server failures, it is customary to reflect a zone to one or more secondary name server.

A zone consists of resource records that are stored in a zone file. The original file is located on the primary name server (also called " Master" called ). From there it is (also known as "Slave" ) with changes by zone transfer to the secondary name servers transferred. The terms zone and zone file are interchangeable in almost all situations.

A zone can include an entire domain. Normally subdomains but are represented by their own zones. With pointers - the NS Resource Records ( RR - NS ) - reference is made to this sub- zones, which may be located on other name servers. This process is called delegation: A zone delegates the responsibility for a subdomain, and only knows the name or the relevant server. Requests for subdomain to be forwarded to the responsible name server. The transition between the two zones is thereby zone Cut -called because "cut out" a zone from a domain by a delegation.

The top level domain de contains, for example, including all subdomains millions of DNS records. It is impossible to keep them in a single zone file. Which belongs to the domain de zone file therefore contains mostly references to direct subdomains. Pro is competent for a subdomain name server while there is a NS record.

Einkauf.example.com IN NS nameserver 1.example.com. produktion.example.com IN NS nameserver 2.example.com. From the domain associated zone file can be deduced that two subdomains exist and that the authoritative name server for einkauf.example.com the nameserver -1 and for produktion.example.com. the nameserver -2. The domains einkauf.example.com and produktion.example.com can of course turn contain other subdomains, which can be represented by its own zone files. Difference between domain and zone

A domain includes the whole child DNS namespace. The term domain is also used, if you look at the content ( which name contains a domain? ) Or property rights (for whom is a domain registered? ) Applies.

A domain can be divided into multiple zones by delegation of authority for subdomains. From a zone one speaks, if you think the physical realization - ie which server and zone file, the DNS records are.

The by the juxtaposition of domain names ( labels) defined domain tree and the tree area on the NS RRs constructed are almost identical. In rare cases, a single zone file also contain multiple domains. The zone tree is therefore slightly smaller than the domain tree.