A proxy server is a computer that can be connected as an interface between two computers or networks. It assumes a proxy function, receiving requests and transmitting them with its own IP address to another network. Proxy servers can be used on the Internet to hide the IP address.
Definition
The basic meaning of the word »proxy» is «the agency, function, or office of someone acting as a substitute for another» (Merriam Webster’s English dictionary). So the main purpose of a proxy is to act as a substitute.
Internet or network solution
Proxy servers are used for both the Internet and proprietary networks. In principle, anyone can set up their own proxy server.
Network Proxy
A proxy server can also be used as part of a network, which is known as a network proxy. Two communication partners can exchange files or requests without transmitting the actual network address. A connection can also be established when both network addresses are not compatible.
Dedicated proxy
A dedicated proxy not only connects two communication partners, but also has a direct effect on the form of communication. You can manipulate, filter or cache the data packets sent to you. Caching is widely applied, especially on the Internet. In this way, the requested files are available more quickly to the Internet user. For data transmission, the dedicated proxy can read and apply various protocols such as http or ftp.
Circuit-level proxy
A circuit level proxy is typically installed on a firewall. It works independently of the network protocol as a filter for traffic from specific addresses or ports. Thus, the generic proxy, as it is also called, can request authentication for the use of a website.
Functions
Proxy servers have multiple functions. The most common ones are briefly explained below.
- Interface between the home network and the public network: You can access a public website through a proxy. This system is often used by universities. Students can access the university network and download e-Media, watch it at home or on the go through a proxy server. The use of a proxy provides additional protection against unwanted access to the network.
- Control of network bandwidth: By using a proxy, a webmaster can control network traffic. Users and groups of users are only assigned certain resources. Control tasks also include monitoring server availability.
- Protection against network attacks: The proxy server is placed between the actual data server and the users. Websites that work with confidential customer data, such as online stores, often use this solution to protect their servers.
- Network logging: Proxy servers are commonly used to record network activity. In this way, harmful access can be identified more quickly.
- Traffic Anonymization: Internet users often use proxy services to anonymize their own IP address. In this way, restrictions on the use of a website can be circumvented and the webmaster of the website accessed with a proxy will not be able to determine the actual sender of the IP request.
- Intermediate storage to reduce server load: a proxy server can store the requests that have been sent to it. Since there are server requests, especially in Internet use, that are repeated, the proxy can deliver the requested information without causing an actual load to the server. At the same time, the requesting agent receives the information more quickly.
- Content blocking: In public networks, access to the Internet can be blocked through a proxy server. On their home network, parents can prevent their children from being directed to websites with pornographic or racist content while surfing. Proxy servers are also used in some repressive countries to censor the Internet. The filtering functions of a proxy can also include the removal of interfering advertising while surfing.
Of course, the increase in Internet browsing from mobile devices such as smartphones and tablets has led to a growing need for 4G proxies. The 4G mobile proxy is specially designed for this type of device and for the increasingly common use of Internet users, who connect to the network from these devices with 4G technology.
Relevance to search engine optimization
SEOs can take advantage of proxies in their work. However, proxy servers are also sometimes used for black hat techniques.
- Page views: For search engine optimization, the use of proxy servers has the advantage that search engines cannot draw any conclusions about common server requests. This is mainly used for automatic site queries, such as SERP ratings, so that the user’s IP address is not blocked due to the many requests.
- Reverse IP proxy: This type of IP manipulation is used by SEOs as a black hat technique to give their projects different Class C virtual networks and IP addresses. In fact, all websites are located on one server. The proxy issues different IPs and Class C networks for the networks’ requests.
- Spamming: Proxy servers are also often used to send out spam requests or spam comments on blogs. This avoids blocking the IP.
- Analysis of user behavior: Proxy servers can complicate the analysis of web traffic. Therefore, it is possible that a German online store gets a lot of traffic from overseas or Eastern European countries. This association can be made, because many of the site visitors use a proxy server, and it transmits an IP address from those regions to the server. This «wrong» IP address is stored in the log file.