A proxy server is a computer or a software system located between a client and an actual server that acts as an intermediary for client requests. It enhances security, privacy, and browsing speed, logs user activities, controls access to restricted services, hides the internal IP address, filters requests from external sites, improves the delivery of web pages to users, and enables authentication for the proxy servers. There are several types of proxy servers such as Transparent, Non-transparent, SOCKS, Anonymous, and Reverse proxy. A proxy server differs from a packet filter in its level of detail in logging and its ability to restructure the data packet.
Benefits of Proxy Server
The following are the benefits of using a proxy server while accessing a network:
It acts as a security protector between the user devices and a server.
It enhances the security and privacy of client devices.
It improves the browsing speed.
It provides advanced logging capabilities for user activities.
It is used for controlling the access to specific types of restricted services.
It helps the organization to hide its internal IP address.
It reduces the chances of modifying cookies in the browser configuration and protects from any kind of malware.
It filters requests from external sites.
It improves the delivery of the requested web pages to the users.
It enables authentication for the proxy servers before handling user requests and services.
Functioning of a Proxy Server
- 1. Internal host requests to access a web site
- 2. The request enters the proxy server which examines the header and packet content based on the rule base
- 3. Server reconstructs the data packet with a different source IP address
- 4. Proxy server transmits the packet to target address that conceals the actual end user who made the request
- 5. If the data packet is returned, it is again sent to the proxy server to check with the rule base
- 6. The returned packet is reconstructed by the proxy server and is sent to the source computer
Proxy Servers vs Packet Filters
- A proxy server creates detailed log file listings because they scan the entire data part of the IP packets, whereas a packet filter logs only header information of the IP packets.
- A packet filter simply allows the data packet to pass through to the destination if it matches the packet filter rules. On the other hand, a proxy server restructures the packet with new source IP data.
- In the case of failure of a proxy server, all network communications would cease, whereas in the case of packet filter failure, all packets may be allowed to pass through to the internal network.
Types of Proxy Servers
Transparent Proxy
- A transparent proxy is a proxy through which a client system connects to a server without its knowledge
- It is configured to be entirely invisible to an end user
- With a transparent proxy, all the web clients must be configured manually
Non-transparent Proxy
- Require client software to be configured to use the proxy server
- The client is made aware of the proxy’s existence
- They are difficult to configure, as each client program must be set up to route all requests to a single port
SOCKS Proxy
- The SOCKS is an Internet Engineering Task Force (IETF) standard
- It is a proxy server that does not have the special caching abilities of a caching HTTP proxy server
- The SOCKS proxy server does not allow external network components to collect information on the client that generated the request
Anonymous Proxy
- An anonymous proxy does not transfer information about the IP address ofits user, thereby hiding information about the user and their surfing interests
Pros
- A user can surf the Internet privately by using an anonymous proxy
- With the help of an anonymous proxy server, a user can access even censored websites
Cons
- 1. Using this type of proxy server may decrease the speed of loading a web page on to the browser
- 2. Using anonymous proxy servers to bypass Internet censorship is illegal in some countries
Reverse Proxy
- A reverse proxy is usually situated closer to the server(s) and will only return a configured set of resources
- It can optimize content by compressing it to speed up loading
- The client is unaware of the presence of a reverse proxy
- A reverse proxy server is an intermediate server that is located between a client and the actual web server
