Detailed DNS
What is DNS
dns stands for Domain Name System, also known as the Domain Name System, an Internet service,
The main preserved correspondence between domain names and ip address of the dns server, providing people with domain name resolution services.
A global total of 13 root dns servers, 10 United States, two in Europe, located in the United Kingdom and Sweden,
Asia Taiwan, in Japan.
DNS architecture
Comprising server relationship is: FIG follows
Root DNS server> top-level DNS server> authoritative DNS server> secondary domain name's DNS server
Root DNS server: holds the correspondence between ip and domain names of all the top dns
Top DNS server: holds the correspondence between ip and dns domain authority of
eg: .com .cn .org
Authoritative DNS server: holds the correspondence between ip and domain name of the secondary domain name server dns
eg: baidu.com sina.com
Secondary domain name's DNS server: holds the correspondence between the domain name and you want to access the ip
eg: www.baidu.com new.sina.com
Enter the url in the browser by pressing the Enter the entire process
The general direction is divided into three processes
1. url domain input through the ip address dns resolves
2. The browser request information (including a request header and a request body Request Headers Request Body) to send ip
3. The server responds with a response message (including a response header Response Headers and Response Body Response Body) to the browser
But dns resolution process can be divided into the following six processes, specifically see the figure
1. Xianxiang local cache to see there dns ip address corresponding to the domain, there is a direct jump, and then down to not
2. The corresponding domain name to the root dns server ip address inquiry (root dns servers let him go to the top-level query dns server)
3. corresponding to the top-level domain name dns server ip address inquiry (top dns server will let him go to query authoritative dns server)
4. asked ip address corresponding to the domain name authority dns server (authoritative dns server would allow him to query two dns server)
The interrogation ip address corresponding to the domain name server dns two (two dns server returns the corresponding address ip)
6. After receiving the ip address, ip and domain name will first save correspondence related to the local dns cache, so that the next convenient access
What is DNS
dns stands for Domain Name System, also known as the Domain Name System, an Internet service,
The main preserved correspondence between domain names and ip address of the dns server, providing people with domain name resolution services.
A global total of 13 root dns servers, 10 United States, two in Europe, located in the United Kingdom and Sweden,
Asia Taiwan, in Japan.
DNS architecture
Comprising server relationship is: FIG follows
Root DNS server> top-level DNS server> authoritative DNS server> secondary domain name's DNS server
Root DNS server: holds the correspondence between ip and domain names of all the top dns
Top DNS server: holds the correspondence between ip and dns domain authority of
eg: .com .cn .org
Authoritative DNS server: holds the correspondence between ip and domain name of the secondary domain name server dns
eg: baidu.com sina.com
Secondary domain name's DNS server: holds the correspondence between the domain name and you want to access the ip
eg: www.baidu.com new.sina.com
Enter the url in the browser by pressing the Enter the entire process
The general direction is divided into three processes
1. url domain input through the ip address dns resolves
2. The browser request information (including a request header and a request body Request Headers Request Body) to send ip
3. The server responds with a response message (including a response header Response Headers and Response Body Response Body) to the browser
But dns resolution process can be divided into the following six processes, specifically see the figure
1. Xianxiang local cache to see there dns ip address corresponding to the domain, there is a direct jump, and then down to not
2. The corresponding domain name to the root dns server ip address inquiry (root dns servers let him go to the top-level query dns server)
3. corresponding to the top-level domain name dns server ip address inquiry (top dns server will let him go to query authoritative dns server)
4.向权威dns服务器询问域名对应的ip地址(权威dns服务器会让他去查询二级dns服务器)
5.向二级dns服务器询问域名对应的ip地址(二级dns服务器会返回对应的ip地址)
6.接收到ip地址后，会先把ip和域名对应关系保存到本地dns缓存，以便下次方便访问