代理服务器

For Wikipedia's policy on editing from open proxies, see Wikipedia:Open proxies . Communication between two computers connected through a third computer acting as a proxy server. This can protect Alice's privacy , as Bob only knows about the proxy and cannot identify or contact Alice directly. Anonymous proxy : This server reveals its identity as a proxy server but does not disclose the originating IP address of the client. Although discovered easily as a proxy server, it can be beneficial for some users as it hides the originating IP address. Forwarding headers : Some proxies append HTTP headers to disclose client or proxy information that would otherwise be lost when a request is forwarded. Historically this has often been done with non-standard fields such as X-Forwarded-For , while the standardised Forwarded field provides a defined syntax for similar information.[[5]]( Such headers are deployment-dependent and should not be treated as inherently trustworthy, since they may be absent, modified, or contain values added by multiple proxies.[[6]]( A reverse proxy taking requests from the Internet and forwarding them to servers in an internal network. Those making requests connect to the proxy and may not be aware of the internal network. A reverse proxy (or surrogate) is a proxy server that appears to clients to be an ordinary server. Reverse proxies send requests to one or more ordinary servers that handle the request. The response from the original server is returned as if it came directly from the proxy server, leaving the client with no knowledge of the original server.[[7]]( Reverse proxies are installed in the vicinity of one or more web servers. All traffic coming from the Internet and with a destination of one of the neighborhood's web servers goes through the proxy server. The use of "reverse" originates in its counterpart, the "forward" proxy. The reverse proxy sits closer to the web server and serves only a restricted set of websites. There are several reasons for installing reverse proxy servers: TLS termination : Reverse proxies often terminate TLS connections from clients and forward requests to backend servers. This can centralise certificate management, access control, logging, and request routing, and can reduce the TLS-related work performed by backend servers. Backend connections may use HTTP or HTTPS depending on the deployment and security requirements. Modern deployments usually perform TLS termination in software, optionally with hardware assistance, rather than requiring dedicated SSL acceleration hardware. Certificates for multiple names can be handled using mechanisms such as Subject Alternative Name certificates, wildcard certificates , and Server Name Indication (SNI).[[8]]( [[9]]( [[10]]( A forward proxy is a server that routes traffic between clients and another system, which is, in most cases, external to the network. This means it can regulate traffic according to preset policies, convert and mask client IP addresses, enforce security protocols, and block unknown traffic. A forward proxy enhances security and policy enforcement within an internal network.[[11]]( A reverse proxy, instead of protecting the client, is used to protect the servers. A reverse proxy accepts a request from a client, forwards that request to another one of many other servers, and then returns the results from the server that specifically processed the request to the client. Effectively, a reverse proxy acts as a gateway between clients, users, and application servers and handles all the traffic routing whilst also protecting the identity of the server that physically processes the request.[[12]]( A content-filtering web proxy server provides administrative control over the content that may be relayed in one or both directions through the proxy. It is commonly used in both commercial and non-commercial organizations (especially schools) to ensure that Internet usage conforms to acceptable use policy . Content fi