Search results
Results From The WOW.Com Content Network
A subdomain is a domain that is part of a larger domain. Each label may contain from 0 to 63 octets. [2] The full domain name may not exceed a total length of 253 ASCII characters in its textual representation. [3] Subdomains are defined by editing the DNS zone file pertaining to the parent domain.
The Public Suffix List is intended to enumerate all domain suffixes controlled by registrars, as well as those controlled privately such as github.io. [8] An internet site consists of the online resources which can be controlled by the registrant of a domain name. That includes resources available via the domain and all its sub-domains.
Single-letter second-level domains are domains in which the second-level domain of the domain name consists of only one letter, such as x.com.In 1993, the Internet Assigned Numbers Authority (IANA) explicitly reserved all single-letter and single-digit second-level domains under the top-level domains com, net, and org, and grandfathered those that had already been assigned.
A zone always starts at a domain boundary to include all leaf nodes (hosts) in the domain or ends at the boundary of another independently managed zone. As each domain is further divided into sub-domains, each becoming a DNS zone with its own set of administrators and DNS servers, the tree grows with the largest number of leaf nodes at the bottom.
A Name Authority Pointer (NAPTR) is a type of resource record in the Domain Name System of the Internet. [1] [2]NAPTR records are most commonly used for applications in Internet telephony, for example, in the mapping of servers and user addresses in the Session Initiation Protocol (SIP).
[citation needed] Such a domain may be reserved by a domain name registry for the registration of third-level domains, or assigned to a third party as a subdomain. Many country code domain registries implement domain name classes at the second level underneath their ccTLD, such as are present in the original generic top-level domains com, net ...
In the last paragraph of RFC 1034 section 3.1. "Name space specifications and terminology", it gives a fairly clear explanation of a subdomain, which matches this article. As another example, RFC 1035 section 2.3.1 gives the ANBF for a subdomain which matches this article's usage. Domains such as support.example.com indeed also subdomains.
Split-horizon DNS is designed to provide different authoritative answers to an identical query and DNSSEC is used to ensure veracity of data returned by the Domain Name System. These apparently conflicting goals create the potential for confusion or false security alerts in poorly constructed networks.