This section briefly introduces the basic process for accessing a website.

This section briefly introduces the basic process for accessing a website.
 

Step 1: Enter www.baidu.com in the browser and press Enter. The system queries the local hosts file and DNS Cache Information to check whether the IP resolution record corresponding to the website exists. If yes, you can directly obtain the IP address and access the website. Generally, the DNS Cache does not have a resolution record during the first request;

Step 2: if the client does not have a DNS cache or the hosts does not have a domain name resolution record corresponding to www.baidu.com, the system will send the browser resolution request, if the Local cache of the LDNS server has corresponding resolution records, the IP address is directly returned; if no, LDNS will continue to request other DNS servers;

Step 3: LDNS will "root began to request www.baidu.com domain name resolution, after a series of searches for various levels of DNS servers, eventually find the corresponding authorized DNS server for www.baidu.com domain name, and this authorized DNS server, it is the server that the enterprise uses to manage domain name resolution when purchasing a domain name. This server has an IP resolution record corresponding to www.baidu.com. If none of the records are found at this time, it indicates that the O & M personnel of the enterprise have resolved the domain name www.baidu.com;

Step 4: the authorized DNS server corresponding to the baidu.com domain name will send the final IP resolution record corresponding to www.baidu.com to LDNS;

Step 5: LDNS sends the IP resolution record of www.baidu.com from the authorized DNS server to the client browser, and caches the resolution of the domain name and IP address locally in LDNS, so that records of the same resolution request can be returned more quickly next time;

Step 6: the client browser obtains the corresponding IP address of www.baidu.com. Next, the browser requests the Web server corresponding to the obtained IP address. The Web server receives the customer's request and responds to the request, return the content requested by the customer to the client browser;

So far, the complete process of one access to the web page is complete.