Although not intended to be a general purpose database, DNS has been expanded over time to store records for other types of data for either automatic lookups, such as DNSSEC records, or for human queries such as responsible person (RP) records. The most common types of records stored in the DNS database are for start of authority ( SOA), IP addresses ( A and AAAA), SMTP mail exchangers (MX), name servers (NS), pointers for reverse DNS lookups (PTR), and domain name aliases (CNAME). A DNS name server is a server that stores the DNS records for a domain a DNS name server responds with answers to queries against its database. Internet name servers and a communication protocol implement the Domain Name System. The Domain Name System maintains the domain name hierarchy and provides translation services between it and the address spaces. The Internet maintains two principal namespaces, the domain name hierarchy and the IP address spaces. It defines the DNS protocol, a detailed specification of the data structures and data communication exchanges used in the DNS, as part of the Internet protocol suite. The Domain Name System also specifies the technical functionality of the database service that is at its core. This mechanism provides distributed and fault-tolerant service and was designed to avoid a single large central database. Network administrators may delegate authority over sub-domains of their allocated name space to other name servers. The Domain Name System delegates the responsibility of assigning domain names and mapping those names to Internet resources by designating authoritative name servers for each domain. The Domain Name System has been an essential component of the functionality of the Internet since 1985. Most prominently, it translates readily memorized domain names to the numerical IP addresses needed for locating and identifying computer services and devices with the underlying network protocols. It associates various information with domain names assigned to each of the associated entities. The Domain Name System ( DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks.
0 kommentar(er)
