A proxy server is a remote computer that is an intermediary between your computer and the Internet. Proxies are usually used either to speed up work on the Internet, or to pass through the Internet anonymously. The use of an anonymous proxy can also be used as an additional means of protection: an anonymous proxy replaces your IP-address, and the attacker will try to attack not the computer, but the proxy server, which often has the most powerful protection system. It is better to purchase proxy servers from trusted companies, one of which is Proxy-Seller.Com.
There are several types of proxies, the main difference of which are the functions performed:
- HTTP / HTTPS proxy is the most common type of proxy server, which often has 80, 8080, 3128 port number. HTTP proxies are divided by anonymity level: transparent (do not hide the real IP address of the client), anonymous (indicate that the proxy is used, but do not give the real IP address of the client), distort (distort the IP address of the client), elite proxies (do not indicate that the proxy server is used hide the real IP address of the client).
- SOCKS proxy – a proxy server that transfers absolutely all data from the client to the server, without changing or adding anything. From the point of view of the web server, SOCKS proxy is a client, i.e. SOCKS proxy are anonymous by definition. It has subtypes SOCKS4, SOCKS4a, SOCKS5. Most often SOCKS proxy have 1080, 1081 port numbers.
- FTP proxy is a proxy server designed for working with file managers.
- CGI proxy or Anonymizer – web-pages that allow anonymous transition from one web-page to another. To use this type of proxy, you do not need to change the browser settings, just enter the anonymizer address before the address of the page to which you are going to go.
According to the principle of the proxy servers can be divided according to two key features. First, some proxy servers have associated caches, while others do not. Secondly, regardless of caching, some proxy servers modify the messages passing through them, while others do not.
Caching Proxy Servers
The difference between regular and caching proxy servers is very important.
A regular proxy server simply forwards requests and responses. The caching proxy server is able to maintain its own repository of responses received
earlier. When a proxy server receives a request that can be satisfied by a cached response, the request is not forwarded, and the response is returned by the proxy server. As we will see later in this chapter, in order for a cache response to be returned, certain conditions must be met. We use the term caching proxy server for a proxy server that has an associated cache.
Transparent proxy server
By the principle of messaging, proxy servers can be divided into two groups: transparent and opaque. The difference between them is due to the modification of the messages passing through the proxy server. A transparent proxy server modifies the request or response only to the extent necessary. An example of such a message change by a transparent proxy server can be the addition of identification information about yourself or the server from which the message was received. Such information may even be required for the HTTP protocol. Sometimes you need to use a proxy of a particular country. To find such servers go to https://proxy-seller.com/canadian-proxy.
An opaque proxy server is able to modify the request and / or responses.
An example of such a change in a request is anonymization, according to which information about the client of the proxy server is hidden. An example of changing the answer is format conversion — an image is converted from one format to another to reduce the size of the answer. Another example of an opaque proxy server is a proxy server that translates a document from one language to another.