DNAME Resource Record

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The DNAME Resource Record is used in the Domain Name System to delegate responsibility for a specific sub- zone to another domain . In contrast to the CNAME , which only applies to a single host name , the DNAME applies to all hosts subordinate to this host name.

syntax

  <Name>  IN  DNAME  <Ziel>

Examples

The following is an example and the difference to the CNAME record: 

  subdomain.example.com. IN DNAME host.example.org.

This record ensures that requests for hosts in the domain “subdomain.example.com” are delegated to “host.example.org”. A request to "www.srv1.subdomain.example.com." Is converted by the DNS server into "www.srv1.host.example.org". The DNAME resource record is therefore very similar to the CNAME, which, however, only redirects a single host. For example, if only the following record is created, 

 subdomain.example.com. IN CNAME host.example.org.

a query for "srv1.subdomain.example.com." would fail because the CNAME only affects the named host and no other hosts in this zone.

Uses of the DNAME Resource Record

The DNAME Resource Record is mainly used, for example with IPv6, to forward the backward resolutions for a specific subnet to another name server. For this purpose, the following record is created at the provider (for the prefix 2001: db8 :: / 48): 

 0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa. DNAME example.com.

Then PTR requests for IP addresses with this prefix are "rewritten" to "example.com". A request for "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.bd0.1.0.0.2.ip6.arpa." (The reverse resolution domain for "2001: db8: : 1 ") is then rewritten to" 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.example.com. "And can be answered by the name servers that are authoritative for example.com.

Individual evidence