Web proxy server and deployment

Introduction

A proxy server is a computer system that sits between the client that requests a web document and the target server (another computer system) that serves the document. In its simplest form, a proxy server facilitates communication between the client and the target server without modifying requests or replies.

When you initiate a request for a resource from the target server, the proxy server hijacks the connection, represents itself as a client to the target server, and requests the resource on your behalf. If a reply is received, the proxy server returns it, establishing communication with the target server.

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What is a proxy?

A proxy represents someone else or has the authority to act on behalf of another.

Proxy servers have the following characteristics:

• Act as an intermediary for requests sent by a client that wants resources from other servers in the computer network.
• Can be any computer system or an application.
• Are created when you install and run proxy software on a computer.
• Enable you to cache your web content and return it quickly on subsequent requests, which helps system administrators, who often struggle with delays and bandwidth usage issues.

Proxy servers have the following advantages:

• Obscure client IP addresses by using network address translation  (NAT) to remap the private IP address to another IP address, which hides the client IP address.
• Block malicious traffic by controlling inbound and outbound traffic.
• Block sites, such as unauthorized sites, adult sites, and so on.
• Log activity by maintaining log records of traffic.
• Improve performance by caching the uniform resource locators (URLs). The proxy server reuses the cached URL when a client sends the data to the same URL that they used previously.
• Reduce bandwidth usage.

Proxy server architecture

The following image shows basic web proxy architecture:

As shown in the preceding image, you can install a web proxy server between the switch and the router. The following web proxy servers are a few of the ones that are available : 

• FreeProxy
• Wingate®
• UltraSurf
• Apache® HttpServer
• Freegaree
• Anonymizer®
• Provoxy
• HAProxy®
• SquidProxy

Proxy server installation prerequisites 

Before you install web proxy server software, ensure that the server has two network interface cards (NICs). One NIC should connect to an internal switch, and the other NIC should connect to the router that connects to the Internet.

You should be prepared to configure the server with an IP address, a gateway, and a Domain Name Server (DNS).

Download, install, and deploy a Wingate proxy server

Use the following steps to download, install, and deploy a Wingate proxy server:

1. Download the Wingate software and install it.

2. Enter the 30-day trial license or your purchased license when prompted as
   shown in the following image:

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The following image shows the network after deployment.  The left side shows the internal architecture, and the right side shows the external architecture.

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 Block a site

The following steps demonstrate how to block a social media site from your network by using a proxy server:

1. Start Wingate. The following window with a left-side navigation pane displays:

    Select Wingate>Web Access Control>Access Rule and click Add rule
    To create an access rule, fill in the rule name and the site to block (such as XYZ.com), and click Add
    To map to the social media category, navigate to Classifiers
    enter www.xyz.com in the empty dialog box, and click OK as shown in the following image: 

Enable the time interval to block a website as shown in the following image

Click Finish to block the site URL. When users try to access the site, they see a Blocked message.

Conclusion

Proxy servers on large networks help to improve reliability by blocking malicious data, and they enable you to cache your web content and return it quickly on subsequent requests.