Dedicated Proxy Or Proxy Server | Part 1
What Is A Dedicated Proxy Or Proxy Server?
A Dedicated Proxy is a utility that provides the data traffic between the requesting client and the target system. It specializes in the communications protocol that uses the service, and can therefore analyze the communication and manipulate their contents as needed. It is also able to independently send a request to the communication partner, and sometimes act as a cache (i.e., on its own to respond to a request without having to request it again from the actual target system must be).
Sometimes it is installed locally on the source or target system, in order to implement the appropriate task in the field. In contrast to this is also an actively trading in the communication intrusive filter module that is mounted on a proxy firewall. Among other things, this comes as a dedicated hosting proxy (e.g., SMTP -) or virus (e.g., FTP -) connection and command filters.
On a single device can run multiple dedicated proxies in parallel in order to be able to use different protocols. So it needs to look into the packets, performs a Dedicated proxy his work at the OSI layer 7.
Dedicated proxies are often used for the following protocols:
HTTP / HTTPS
Most providers offer their customers the use of such proxies. He can perform the following functions:
SSL Termination
An HTTPS connection can be terminated) using Web proxy broken up (to check and its contents to pests. The additional encryption to the client (browser) is then carried out with a certificate offered by the proxy. Problem is that the user of the browser no longer gets to see the original certificate of the Web server and the proxy server must trust that he has a validity check of the Web server Certificates accepted.
Cache
The proxy can store Asked Questions and their result. When asked the same question again, this can be answered from memory, without first asking the web server. The proxy ensures that the information supplied by him are too outdated. A complete date is not guaranteed by the rule. By caching queries can be answered faster and it will also reduce the network load. For example, a proxy of such a company provides all the traffic, from the computer staff to the Internet.
Censorship / Access Control
Using proxy can lock certain pages for the user accesses or logs out. It can be searched and the contents of badware (viruses, malicious code, scripts, etc.). Thus, a proxy is usually part of a firewall approach. Above all, it is useful not just to schools or public facilities, but also to prevent companies in this way access from its network to any websites, for example, to prevent the downloading of music files because of legal problems related to them. In addition, it wards against dangerous websites (pornography, racist websites, protect, etc.) to. By means of user authentication, it can be assigned to individual users or user groups using different Web filtering.
Filtering out advertising
Advertising can generate substantial amounts of traffic – many advertising space to load, for example, regularly. What is problematic for the Consumer to an ADSL line is, for example, may be a network of several dozen users on this line, adding to the problem.
SMTP
Some firewalls provide an SMTP proxy to that monitors the email traffic between the Internet and mail server and filters out certain dangerous or undesirable commands. The design of the SMTP protocol is useful any SMTP server as an SMTP proxy is used.
IMAP Proxy
Holt, for example, automatically collect e-mails from the central IMAP server on a local machine from which the client then sends / receives the e-mail.
IRC Proxy
Such a proxy gives IRC connections and one can maintain it, even if the client is disabled.
NNTP Proxy
The proxy (Leafnode, for example) can be used for news and allows, for example, to define filters for unwanted groups.
Exchange front-end server
It provides a proxy function if it is available, and creates the tunneling of the RPC protocol over HTTP (S).
Citrix Secure Gateway
Here, the ICA protocol over HTTP (S) is tunneled.
Continued…
