What is a Proxy Server and How Does it Work? – Varonis
The actual nuts and bolts of how the internet works are not something people often stop to consider. The problem with that is the inherent danger of data security breaches and identity theft that come along with the cute dog pictures, 24-hour news updates, and great deals online.
But what actually happens when you browse the web? You might be using a proxy server at your office, on a Virtual Private Network (VPN) or you could be one of the more tech-savvy who always use a proxy server of some kind or another.
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What’s a Proxy Server?
A proxy server is any machine that translates traffic between networks or protocols. It’s an intermediary server separating end-user clients from the destinations that they browse. Proxy servers provide varying levels of functionality, security, and privacy depending on your use case, needs, or company policy.
If you’re using a proxy server, traffic flows through the proxy server on its way to the address you requested. The request then comes back through that same proxy server (there are exceptions to this rule), and then the proxy server forwards the data received from the website to you.
If that’s all it does, why bother with a proxy server? Why not just go straight from to the website and back?
Modern proxy servers do much more than forward web requests, all in the name of data security and network performance. Proxy servers act as a firewall and web filter, provide shared network connections, and cache data to speed up common requests. A good proxy server keeps users and the internal network protected from the bad stuff that lives out in the wild internet. Lastly, proxy servers can provide a high level of privacy.
How Does a Proxy Server Operate?
Every computer on the internet needs to have a unique Internet Protocol (IP) Address. Think of this IP address as your computer’s street address. Just as the post office knows to deliver your mail to your street address, the internet knows how to send the correct data to the correct computer by the IP address.
A proxy server is basically a computer on the internet with its own IP address that your computer knows. When you send a web request, your request goes to the proxy server first. The proxy server then makes your web request on your behalf, collects the response from the web server, and forwards you the web page data so you can see the page in your browser.
When the proxy server forwards your web requests, it can make changes to the data you send and still get you the information that you expect to see. A proxy server can change your IP address, so the web server doesn’t know exactly where you are in the world. It can encrypt your data, so your data is unreadable in transit. And lastly, a proxy server can block access to certain web pages, based on IP address.
What are Forward Proxies
A forward proxy server sits between the client and an external network. It evaluates the outbound requests and takes action on them before relaying that request to the external resource.
Most proxy services that you’re likely to encounter are forward proxies. Virtual Private Networks and Web content filters are both examples of forward proxies.
What are Reverse Proxies
A reverse proxy server sits between a network and multiple other internal resources. A large website might have dozens of servers that collectively serve requests from a single domain. To accomplish that, client requests would resolve to a machine that would act as a load balancer. The load balancer would then proxy that traffic back to the individual servers.
Some popular open source reverse proxies are:
Why Should You Use a Proxy Server?
There are several reasons organizations and individuals use a proxy server.
To control internet usage of employees and children: Organizations and parents set up proxy servers to control and monitor how their employees or kids use the internet. Most organizations don’t want you looking at specific websites on company time, and they can configure the proxy server to deny access to specific sites, instead redirecting you with a nice note asking you to refrain from looking at said sites on the company network. They can also monitor and log all web requests, so even though they might not block the site, they know how much time you spend cyberloafing.
Bandwidth savings and improved speeds: Organizations can also get better overall network performance with a good proxy server. Proxy servers can cache (save a copy of the website locally) popular websites – so when you ask for, the proxy server will check to see if it has the most recent copy of the site, and then send you the saved copy. What this means is that when hundreds of people hit at the same time from the same proxy server, the proxy server only sends one request to This saves bandwidth for the company and improves the network performance.
Privacy benefits: Individuals and organizations alike use proxy servers to browse the internet more privately. Some proxy servers will change the IP address and other identifying information the web request contains. This means the destination server doesn’t know who actually made the original request, which helps keeps your personal information and browsing habits more private.
Improved security: Proxy servers provide security benefits on top of the privacy benefits. You can configure your proxy server to encrypt your web requests to keep prying eyes from reading your transactions. You can also prevent known malware sites from any access through the proxy server. Additionally, organizations can couple their proxy server with a Virtual Private Network (VPN), so remote users always access the internet through the company proxy. A VPN is a direct connection to the company network that companies provide to external or remote users. By using a VPN, the company can control and verify that their users have access to the resources (email, internal data) they need, while also providing a secure connection for the user to protect the company data.
Get access to blocked resources: Proxy servers allow users to circumvent content restrictions imposed by companies or governments. Is the local sportsball team’s game blacked out online? Log into a proxy server on the other side of the country and watch from there. The proxy server makes it look like you are in California, but you actually live in North Carolina. Several governments around the world closely monitor and restrict access to the internet, and proxy servers offer their citizens access to an uncensored internet.
Now that you have an idea about why organizations and individuals use a proxy server, take a look at the risks below.
Proxy Server Risks
You do need to be cautious when you choose a proxy server: a few common risks can negate any of the potential benefits:
Free proxy server risks
You know the old saying “you get what you pay for? ” Well, using one of the many free proxy server services can be quite risky, even the services using ad-based revenue models.
Free usually means they aren’t investing heavily in backend hardware or encryption. You’ll likely see performance issues and potential data security issues. If you ever find a completely “free” proxy server, tread very carefully. Some of those are just looking to steal your credit card numbers.
Browsing history log
The proxy server has your original IP address and web request information possibly unencrypted, saved locally. Make sure to check if your proxy server logs and saves that data – and what kind of retention or law enforcement cooperation policies they follow.
If you expect to use a proxy server for privacy, but the vendor is just logging and selling your data you might not be receiving the expected value for the service.
If you use a proxy server without encryption, you might as well not use a proxy server. No encryption means you are sending your requests as plain text. Anyone who is listening will be able to pull usernames and passwords and account information really easily. Make sure whatever proxy server you use provides full encryption capability.
Types of Proxy Servers
Not all proxy servers work the same way. It’s important to understand exactly what functionality you’re getting from the proxy server, and ensure that the proxy server meets your use case.
A transparent proxy tells websites that it is a proxy server and it will still pass along your IP address, identifying you to the web server. Businesses, public libraries, and schools often use transparent proxies for content filtering: they’re easy to set up both client and server side.
An anonymous proxy will identify itself as a proxy, but it won’t pass your IP address to the website – this helps prevent identity theft and keep your browsing habits private. They can also prevent a website from serving you targeted marketing content based on your location. For example, if knows you live in Raleigh, NC, they will show you news stories they feel are relevant to Raleigh, NC. Browsing anonymously will prevent a website from using some ad targeting techniques, but is not a 100% guarantee.
A distorting proxy server passes along a false IP address for you while identifying itself as a proxy. This serves similar purposes as the anonymous proxy, but by passing a false IP address, you can appear to be from a different location to get around content restrictions.
High Anonymity proxy
High Anonymity proxy servers periodically change the IP address they present to the web server, making it very difficult to keep track of what traffic belongs to who. High anonymity proxies, like the TOR Network, is the most private and secure way to read the internet.
Proxy servers are a hot item in the news these days with the controversies around Net Neutrality and censorship. By removing net neutrality protections in the United States, Internet Service Providers (ISP) are now able to control your bandwidth and internet traffic. ISPs can potentially tell you what sites you can and cannot see. While there’s a great amount of uncertainty around what is going to happen with Net Neutrality, it’s possible that proxy servers will provide some ability to work around an ISPs restrictions.
Varonis analyzes data from proxy servers to protect you from data breaches and cyber attacks. The addition of proxy data gives more context to better analyze user behavior trends for abnormalities. You can get an alert on that suspicious activity with actionable intelligence to investigate and deal with the incident.
For example, a user accessing GDPR data might not be significant on its own. But if they access GDPR data and then try to upload it to an external website, it could be an exfiltration attempt and potential data breach. Without the context provided by file system monitoring, proxy monitoring, and Varonis threat models, you might see these events in a vacuum and not realize you need to prevent a data breach.
Get a 1:1 demo to see these threat models in action – and see what your proxy data could be telling you.
Find Proxy Settings on Your Computer (for Local Testing …
You can find the proxy settings applicable to your machine and use them to set up Local Testing connections.
A proxy server sits between your machine and your ISP. In most organizations, proxies are configured
by network admins to filter and/or monitor inbound and outbound web traffic from employee computers.
In this article, we’ll show you how to view proxy settings (if your computer is behind a proxy server).
You can then use the information to set up Local Testing connections with BrowserStack..
Find Proxy Settings in Windows
In most cases, browsers will use proxy settings that are set on the computer. However, each browser has a
settings page to configure proxy settings as well.
There are two ways to find proxy settings in Windows: via the Settings app (Windows 10 only) or via the
Using the Settings App (Windows 10) to find proxy settings
Click on Start, then click on the gear icon (Settings) at the far left.
In the Windows Settings menu, click on Network & Internet.
In the left pane, click on Proxy.
Here you have all the settings that are related to setting up a proxy in Windows. It’s split into
two configurations: Automatic or Manual proxy setup.
Using the configuration details to set up Local Testing connection:
If “Use setup script“ is enabled, it means that you have configured PAC proxy on your system. You
can obtain the path to PAC file from the “Script Address“ section.
Note: To set up a Local Testing connection using the PAC file, you need to ensure that the PAC file is stored on your computer and path needs to an absolute path to that file.
If “Manual proxy setup” is enabled, you can simply obtain Proxy Host and Port from the “Address“
and “Port“ section.
For Local Testing to work correctly, you need to bypass the traffic for – – from your
proxy. You can do this by adding an entry in the Proxy Exception> text field in the
“Manual proxy setup” section.
Using Control Panel (all Windows versions) to find proxy settings
In any Windows version, you can find the proxy settings via the Control Panel on your computer.
Click on Start and open the Control Panel. Then click on
In the Internet Options, go to Connections > LAN settings.
Here you have all the settings that are related to setting up a proxy in Windows. It’s basically
split into two configurations: either Automatic configuration or
Proxy Server setup.
If “Use automatic configuration script“ iis checked, it means that you have configured PAC proxy
in your system. You can obtain the path to PAC file from the “Script Address“ section.
If “Use a proxy server for your LAN” is checked, you can obtain Proxy Host and Port from the
“Address“ and “Port“ section.
proxy. You can do this by clicking the “Advanced“ button and adding an entry in the
“Do not use proxy server for addresses beginning with:“ text field.
Find Proxy Settings in OS X
On OS X, you have to view the proxy settings in System Preferences. This is where most browsers check automatically. However, each browser has a settings page to configure proxy settings as well.
Open System Preferences and click on Network.
On the left-hand side, click on an active network connection. Note that you can have different proxy settings for different network connections. Click on the Advanced button on the bottom right.
Click on the Proxies tab and you’ll see a list of proxy protocols you can configure.
If “Automatic Proxy Configuration“ is checked, it means that you have configured PAC proxy in your system. You can obtain the path to PAC file from the “Script Address“ section.
If “Web Proxy (HTTP)” or “Secure Web Proxy (HTTPS)“ is checked, you can simply obtain Proxy Host, Port, Username, and Password.
For Local Testing to work correctly, you need to bypass the traffic for – – from your proxy. You can do this by adding an entry in the ”Bypass proxy settings for these Hosts & Domains” text field.
Connection duration and disconnection
In Linux, finding your proxy settings will depend on what distribution you are running. Mostly, the procedure would be similar for the various distributions.
On Ubuntu, open on System Settings from the launcher and scroll down to Hardware. Click on Network.
Click on Network Proxy, you can choose from Automatic or Manual.
If the “Automatic“ option is selected, it means that you have configured PAC proxy in your system. You can obtain the path to PAC file from the “Configuration URL“ section.
If the “Manual“ option is selected, you can simply obtain Proxy Host and Port from the appropriate section.
For Local Testing to work correctly, you need to bypass the traffic for – – from your proxy. You can do this by using the command-line interface as follows:
To change proxy exceptions, use ‘set’ option with ‘gsettings’ command as follows.
$ gsettings set ignore-hosts “[‘localhost’, ”, ‘::1’]”
If access to the above sections is restricted on your computer, you can seek help from your IT/Network Team to gather this information.
How to Set Up a Proxy Server on Your PC, Mac, or Web Browser
As for what a proxy server is, think of your proxy as a gateway between you and the internet. When you visit a website, the proxy server communicates with it on behalf of your browser. Then, when the website answers, the proxy forwards the data to you.
Proxy servers can do many jobs. These include scanning for viruses, acting as a firewall, speeding up your connection by caching, and hiding your public IP address.
You have lots of choices when it comes to internet privacy. There’s a lot to learn, such as understanding what a reverse proxy is or distinguishing between VPNs, proxies, and Tor. If you want dependable protection and encryption for your internet traffic, consider a VPN. Avast SecureLine VPN hides your data from snoopers and protects your online identity, and it’s also much easier to set up than a proxy server.
There’s no similar guarantee of protection with a proxy, especially if you’re using one of the many web-based proxies available online. These public proxy services may slow down your service, and even worse, they may be insecure. Instead, we suggest you learn how to set up a proxy server on Windows, MacOS, and the most popular web browsers.
If you’re configuring your browser to use a proxy operated by a company, school, or other similar organization, some of these instructions may require you to contact your IT staff. This is the case particularly when you are asked to manually enter a script name, formally called a proxy auto-configuration (PAC) file. You may also need to type in the proxy’s IP and port numbers. In both cases, turn to your IT helpdesk if you haven’t been given this information. If you’re using a proxy that you’ve purchased or created on your own, you’ll already have these details.
How to set up a proxy server in Windows
Here’s how to set up your Windows PC to use a proxy server on Windows 8 or Windows 10:
Press the Windows + I keys simultaneously to access the Windows Settings menu.
On Windows 10, click Settings > Network & Internet > Proxy. On Windows 8, click Settings > Network Proxy.
Under the Manual Setup section, set the “Use a Proxy Server” toggle to On. Make sure the “Automatically detect settings” toggle is also on.
By default, Windows automatically checks to see if your business, school, or local network already has an automatic proxy server setup ready to run for you. If it does, Windows tells you its name, and encourages you to follow its instructions.
Assuming that Windows finds a PAC file, in the Automatic Proxy Setup, set the Use Setup Script switch to On.
Enter the script address and click Save.
Congratulations! You’re done and ready to proxy.
How to manually set up a proxy in Windows 8 or Windows 10
Not every organization sets up the process automatically. If you need to set up a proxy manually in Windows 8 or Windows 10, here’s how to do it.
To access the Windows Settings menu, press the Windows + I keys simultaneously.
On Windows 10, click Settings > Network & Internet > Proxy. On Windows 8 systems, click Settings > Network Proxy.
Scroll down to “Manual proxy setup” and set the “Use a Proxy Server” switch to On.
In the address field, type the proxy server name or IP address. In the Port field, enter the proxy port number. You can get these from your IT support tech.
If the proxy server is protected by a password, select the “Proxy server requires password” checkbox. Enter your account name and password in the Username and Password fields.
That’s all there is to it. You’re now set up to use your proxy server on Windows. The next time you use the internet, you’ll be using the proxy server.
How to set up a proxy server on a Mac running macOS
Here’s how to set up a proxy server on a Mac running macOS 10. 15 Catalina. Other macOS versions use essentially the same commands.
Open System Preferences. One way to get there is to click on the Apple menu > System Preferences.
Choose the Network icon to adjust connectivity settings.
Select the type of network you use, which is usually Ethernet or Wi-Fi.
Click Advanced > Proxies.
To automatically configure your proxy server settings, select Auto Proxy Discovery. Click on Secure Web Proxy (HTTPS). Type in the proxy server address and its port number in the fields on the right.
To use a proxy auto-configuration (PAC) file, select Automatic Proxy Configuration and enter the proxy address into the URL field.
Click OK to save the proxy setup.
You’re now ready to surf the internet via your proxy.
How to set up a proxy in Google Chrome
By default, Chrome uses your macOS or Windows proxy. To change your proxy settings from within Chrome, take the following steps:
Open the Chrome toolbar and select Settings.
Scroll down to the bottom of the display. Click on Show advanced settings…
Scroll down to “System” and choose Open your computer’s proxy settings.
Next, go back to the instructions for your operating system listed above to set up your proxy server settings and follow them.
In short, to set up a proxy server in Google Chrome, you’re just doing the first few steps in the browser, and then completing the process in your machine’s operating system.
How to set up a proxy server in Safari
Like Chrome, Safari’s default setting is to follow the proxy configurations within your OS. Here’s how to change your proxy settings from within Safari:
Click on Safari in the browser toolbar. Choose Preferences.
Click on the Advanced tab. Under “Proxies, ” click Change settings…
Next, you must go back to the instructions for macOS listed above to set up your proxy server settings and follow them.
How to set up a proxy server in Edge
Edge is Windows 10’s built-in web browser, and unless you tell it otherwise, it’ll use your proxy configurations in Windows. The latest versions of Edge are based on Chrome, so the configuration is similar. The following steps show you how to set up a proxy from within Edge:
In Microsoft Edge, at the top-right corner, click the Menu button. Select Settings.
Scroll down to the Advanced settings section and click the View advanced settings icon.
Click the Open proxy settings button.
Next, go back to the instructions for Windows 10 listed above, then follow them to configure your proxy server settings.
How to set up a proxy server in Firefox
Unlike other web browsers, Firefox doesn’t default to using your system’s proxy settings. You’ll need to change your proxy from within Firefox:
Open the Firefox menu and select Options.
Click on the Advanced icon.
Select the Network tab.
In the Connection Settings, select, Auto-detect proxy configuration for this network. When prompted, enter the proxy address.
Alternatively, in the Connection Settings, you can select, Use system proxy settings. If you choose that option, Firefox uses the proxy settings in your operating system.
Click OK to save your settings.
How to set up a proxy server in Internet Explorer
Please keep in mind that Internet Explorer is an outdated web browser. Instead, switch to a browser that’s still receiving regular updates and support, such as Avast Secure Browser, Chrome, Edge, Firefox, or Safari. Though since quite a few people and companies still use Internet Explorer (IE), you should know how to set things up when necessary.
As with other browsers, IE defaults to using your Windows proxy configurations. Here’s how to set your proxy up from within IE.
Open the IE toolbar and select Internet Options.
Open the Connections tab.
Select LAN Settings.
Check the “Use a proxy server for your LAN” box.
When prompted, enter the proxy server name and port number.
How to set up a proxy server in Android
With Android, you must configure proxy settings for each network you use. In addition, the proxy will only be used by your web browser. Other internet applications may choose to use or ignore the proxy based on their own internal settings. This is another reason why VPNs tend to be better choices — when you use one, it covers all the internet traffic from your device.
Open Android’s Settings and tap Wi-Fi to view a list of Wi-Fi networks.
Long-press the Wi-Fi network name for which you want to change the proxy settings. Tap Modify Network.
Tap Advanced Options.
Tap Manual to change your proxy’s settings. Enter your hostname and proxy port.
If you have a Proxy Auto-Config (PAC) file, select Proxy Auto-Config and Android will prompt you to enter the PAC address.
How to set up a proxy server in iOS
Go to Settings > Wi-Fi.
Select the active Wi-Fi connection.
Under HTTP proxy, click Configure Proxy.
Tap Manual to change your proxy’s settings. Enter your host name, proxy port, and, if needed, your authentication username and password.
If your provider supports Web Proxy Auto-Discovery Protocol (WPAD), tap Automatic. If required, enter the Proxy Auto-Config (PAC) file location.
Tap back to the Wi-Fi selection window.
Protect your online anonymity the easy way
Proxy servers have their uses, particularly within large organizations. However, setting one up requires a bit of work, and this is a job typically entrusted to network administrators and other IT professionals.
Avast SecureLine VPN is an internet privacy solution that’s both simpler to use and far more protective of your identity and online activities. A single click or tap of a button gets you encryption that keeps you anonymous online and prevents anyone from snooping on your sensitive personal info, such as your online banking, health info, or private photos. Enjoy true online privacy on your desktop, laptop or mobile device with a VPN that’s as convenient as it is secure.
Frequently Asked Questions about your proxy
How do I know what my proxy is?
In any Windows version, you can find the proxy settings via the Control Panel on your computer.Click on Start and open the Control Panel. Then click on Internet Options.In the Internet Options, go to Connections > LAN settings.Here you have all the settings that are related to setting up a proxy in Windows.
What does it mean to use proxy?
As for what a proxy server is, think of your proxy as a gateway between you and the internet. When you visit a website, the proxy server communicates with it on behalf of your browser. Then, when the website answers, the proxy forwards the data to you. This article contains: … How to set up a proxy server in Android.Mar 11, 2020
Do I have a proxy?
Click the “Connections” tab in the Internet Options window. Click the “LAN Settings” button. If there is a check mark in the box next to the “Us a proxy server for your LAN” option, then your PC accesses the Web through a proxy server. If there is no check mark in the box, your computer does not use a proxy server.