Traditional dns principle

Principle of DNS name resolution: DNS server is responsible for converting host names and domain names into IP addresses. DNS domain name server can make forward query and reverse query. A forward query resolves a name to an IP address, while a reverse query resolves an IP address to a name. The general format of DNS is: local host name, group name and network name. A server running Windows 2000 Active Directory requires a DNS server. The query request is first transmitted to the DNS client service, which will try to parse it using the locally cached information. If the parsing is successful, the query will be answered and the results will be returned. Otherwise, the DNS client will query the DNS server to resolve the name. Generally, the principle of responding to local cache from host files (HOSTS files) or previous DNS queries is reverse query: reverse query queries computer domain names according to IP addresses. In order to realize reverse query, a special domain, in-addr.arpa domain, is defined according to IP address instead of domain name in the domain name space. The subdomain in the in-addr.arpa domain consists of the reverse order of decimal numbers with periods in IP addresses. The in-addr.arpa domain tree established in DNS requires that the resource record type is a pointer (PTR). Host address (a) The resource record type, which usually corresponds to the DNS computer name of the host in its forward search area.