php interview topics --- 10, a network protocol test sites
A summary
Sentence summary:
In fact, these test center network: common status codes, common protocol, osi seven layer model, http and https
1, HTTP / 1.1, the status code 200,301,304,403,404,500 meaning?
:( 301 Moved Permanently) The requested page has been permanently moved to a new location. When the server returns this response (response to a GET or HEAD request), it automatically forwards the requestor to the new location.
:( 304 Not Modified) since the last request, the requested page has not been modified. When the server returns this response, it does not return to the page content.
403 :( prohibited) server rejects the request.
:( 404 Not Found) server can not find the request.
2, OSI seven-layer model?
The physical layer, data link layer, network layer, transport layer, session layer, presentation layer, application layer
3, the working characteristics of the HTTP protocol?
no status
Based on B / S
Communication overhead is small, simple and fast, low-cost transmission
Based on B / S
less communication overhead, simple and rapid, low-cost transmission of
flexible, hypertext transfer protocol may be used
to save transmission time
stateless
4, the working principle of the HTTP protocol?
The client sends a request to the server, create a TCP connection, specify the port number, the default is 80, connect to the server, the server listens browser requests, once listening to the client requests, analyzing the type of request, the server returns status information to the client and data content
5, HTTP protocol common request methods?
GET: Gets
POST: Upload
PUT: Modify
DELETE: Delete
GET、POST、HEAD、OPTIONS、PUT、DELETE、TRACE
6, the working principle of the HTTPS protocol?
SSL / TLS: HTTPS is based on SSL / TLS HTTP protocol, HTTP data is all over SSL / TLS protocol encapsulation transmission.
Encrypted transfer: HTTPS protocol based on the HTTP protocol, add the SSL / TLS handshake and encrypted data transmission, also belong to the application layer protocol.
7, meaning common network protocols and ports?
FTP、Telnet、SMTP、POP3、HTTP、DNS
8, our common HTTP protocol, TCP protocol are located in the first layers of the OSI network model?
HTTP protocol: the seventh floor
TCP protocol: the fourth floor
9, the seventh layer application layer protocol What?
HTTP FTP TFTP SMTP SNMP DNS TELNET HTTPS POP3 DHCP
Second, content in summary
Reproduced in: https: //www.cnblogs.com/Renyi-Fan/p/11061767.html