DNS with NS, NS records

DNS: People are accustomed to the memory domain name, but the machine between each other only IP address, domain name and IP address is one by one corresponding, the conversion between them is called Domain name resolution, domain name resolution needs to be dedicated to the domain name resolution server to complete, the whole process is automatic. When your website is finished and uploaded to your virtual host, you can enter the IP address directly in the browser to browse your site, you can also enter the domain name to query your site, although the content is the same but the process is different, the input IP address is directly from the host to invoke the content, The input domain name is the IP address of the corresponding host through the domain name resolution server, and then the content of the site is called from the host.

A resource record is a DNS database record that is used to reply to a DNS client request, and each DNS server contains all the resource records for the DNS namespace that it manages. A resource record contains information about a specific host, such as an IP address, the type of service provided, and so on. Common resource record types are: SOA (start authorization structure), A (host), NS (name server), CNAME (alias), and MX (mail exchanger). A record is an important record of name resolution, which is used to map a specific host name to the IP address of the corresponding host. You can create it either manually in the DNS server or through a DNS client dynamic update.NS records This record to specify the authoritative name servers that are responsible for this DNS zone.  the difference between A and NS records is that a record directly gives the purpose Ip,ns record to give the DNS resolution task to a particular server, and the IP recorded in the NS record is the IP address of that particular server.

The role of Name server:

For example, a netcom ADSL access users want to access HTTP/ www.263.sh.cn, in fact, first of all, the user first feedback this request to the local computer's DNS, the local computer's DNS will first query in their cache whether there is www.263.sh.cn a record value, if so, direct feedback to the local computer, directly connected to the local computer www.263.sh . CN corresponds to the host to obtain the corresponding data If there is no www.263.sh.cn a record value in the cache, then the DNS of Netcom will connect as the regular enterprise mailbox. Root server, query. NET root server above root server, and then connect. NET root server to query for 263.net name server , and finally the DNS and 263.net name server connections used by the user to obtain the www.263.sh.cn a record value. (Note: The cache is a buffer area, the cache domain name record value of the retention time is determined by the domain name itself record value of the life cycle to determine, beyond the life cycle, the domain name record value will automatically be removed from the ISP DNS cache, if there is a user to access the record, The record value needs to be retrieved as described above).

NS Records
1, NS record is a domain name DNS server inside a record type, can be for each domain name or sub-domain to set his NS record, when set, the equivalent of his interpretation of the right to the corresponding DNS.
2. Use of NS records: CDN or Load Balancer.

The NS name server, the NS record for DNS, is used to authorize the down authorization to specify which DNS server the domain name is to parse

DNS and NS, NS records