How does the server build a virtual host?

   Virtual host or shared host , Also called virtual server , On a single host or host group , Achieve more
Method of domain service , Technology that can run multiple websites or services . Virtual hosts are completely independent , And can be managed by users themselves , Virtual does not mean that there is no , It means that the space is extended from the server of the entity , Its hardware system can be based on server group , Or a single server . Now there are many server management tools , Use management tools , Can quickly build a virtual host . The implementation of virtual host is generally divided into URL name correspondence 、IP Address correspondence and Port The port number corresponds to .

   One 、 be based on IP Methods ：

   Bind multiple on the server IP, Then configure WEB The server , Bind multiple websites to different IP On . Browse different IP, You can see different websites .

   Two 、 Port based approach ：

   One IP Address , Visit different websites through different ports .

   3、 ... and 、 Host name based method ：

   Equipped with multiple domain names A Record , Let them resolve to the same IP Address , That is, on the same server . And then , Install... On the server WEB Server side , Add multiple websites , Draw up a host name on each website . because HTTP The protocol access request contains the hostname information , When WEB When the server receives an access request , Will visit different websites according to different host names .

   Virtual host technology is an Internet server technology to save the cost of server hardware , Virtual host technology is mainly used in HTTP（Hypertext Transfer Protocol, Hypertext transfer protocol ） service , Logically divide one or all services of a server into multiple service units , The external representation is multiple servers , So as to make full use of server hardware resources .

   Virtual host uses special software and hardware technology , Divide a real physical server host into multiple logical storage units . Every logical unit has no physical entity , But every logical unit can work on the network like a real physical host , Have a separate IP Address （ Or shared IP Address ）、 Independent domain name and complete Internet The server （ Support WWW、FTP、E-mail etc. ） function .

   The key technology of virtual host is , Even on the same hardware 、 On the same operating system , Running different server programs for multiple users , They don't interfere with each other . Each user has its own part of the system resources （IP Address 、 Document storage space 、 Memory 、CPU etc. ）. Each virtual host is completely independent , To the outside world , Each virtual host performs exactly the same as a separate host . Therefore, this virtualized logical host is vividly called “ Virtual host ”.