21.7 C

How to bypass a firewall

Hello, In most schools, universities and at work there is a firewall. Indeed, this tool in combination with others, limits Internet browsing and protect users against external threats. In many occasions, the restrictions at the firewall level are quite important. Consequently, if we want to access blocked websites we will have to make use of different tools. It is probably not a good idea to bypass this firewall because it can have consequences. However, here we are going to offer some methods in case you are willing to take the risk. In this post we are going to talk about how to bypass the firewall.

How to bypass the firewall

A firewall is a software and/or hardware system that is responsible for controlling all incoming and outgoing connections between the local network and the Internet. It is also responsible for logically separating different subnets that we have in different VLANs. Its main function is to prevent and protect our private network from possible intrusions. With this in mind, it blocks access from the outside to the inside. A firewall can also be configured to limit traffic from the internal network to the external network. Therefore, we might encounter some kind of blocking implemented by the network administrator.

In many occasions users want to access the Internet without any kind of limitation. Indeed, knowledge of how to access blocked websites in a school or university can be an asset among students. The same is true at work. It is possible to want to access a resource blocked by the firewall. Consequently, it may be necessary to attempt to bypass the organization’s firewall.

Here we are going to analyze how to bypass the school, university or work firewall. Accordingly, we will check methods to bypass the firewall. This depends on how that particular firewall works. Some work at the DNS level. That is to say, the firewall itself will be in charge of providing us with local DNS servers where the filtering is done, in addition, the possibility of using external DNS such as those of Google or Cloudflare is blocked. Another common method of blocking is to check the SNI field of HTTPS connections. As a result, we could allow or block access to certain web pages. Finally, they could do a deep traffic inspection (DPI) to block traffic that they have defined in the rules.

Use a proxy server

- Advertisement -

Proxies are services that will act as intermediaries and handle requests for us. For example, if you want to view a game website, it is quite likely that you will look it up by typing the URL in the address bar and the firewall will block it. A proxy server avoids this because you are not visiting the game website directly. What we do is go to the proxy page, and you tell it to go to that page instead of us. It then shows you all the requested content, while the firewall only sees the proxy URL.

There are several types of Proxy, those based on HTTP and HTTPS. It is the latter that you should use. Indeed, if you use HTTP, all traffic will be unencrypted and could easily be blocked by the firewall. When using an HTTPS proxy, all communications between the user’s computer and the proxy server will be fully encrypted. Consequently, it is ideal for maintaining privacy and keeping the firewall out of the way.

When using a web proxy, you must consider that the browser you use must be correctly configured. Therefore, you must go to the network section and configure the IP address and port of the proxy, as well as the protocol it is using. Once configured, we will be able to surf the Internet through the Proxy. However, the traffic used by other programs such as Skype or Slack will go through the main Internet connection. In reality, there is no complete forwarding of traffic as with VPN services, only web traffic will move through the Proxy.

Use a VPN to keep your traffic out of sight

A VPN is even more complete than a proxy and also makes it possible to bypass the firewall at work or school. In this case, it is as if our data travels hidden through a tunnel thanks to encryption. Consequently, it keeps us safe from prying eyes such as the school itself, the Internet provider and more. In this way of working, our computer sends this encrypted data to a VPN server, which decrypts our data. It then reads where we want to go and goes there. It then sends the traffic back encrypted and bypasses the firewall without any problems.

A significant detail of VPNs is that all network traffic will go from your PC to the VPN server. In fact, it will not only be the web traffic, but also the Internet traffic of any program or process we are using.

Google Translate

Another method is to use Google Translate. Here we have to use the translation page function to use it. Then, when Google Translate translates that page, it loads the page on the server, translates it and sends us the result. This little trick is widely used to bypass firewalls when a website is blocked. In effect, we will use Google’s services to take us to the final website. However, this method has its limitations. Besides, it is quite annoying to have to use the hyperlinks inside the Google translator.

The use of this trick is basic. Just go to the Google Translate page. Once there, please upload the URL of the blocked web page. Allow the algorithm to detect the language automatically. Then, you have to translate the website to a different language than the original one. That’s it! As a result, you will have access to the website but in a different language than the original one. However, it is a way to access. Beyond the language limitation, it is likely that your organization will also block this domain from Google because it has been known to do this kind of thing. As a result, it may not work.

Type the IP address of the website

When surfing the Internet we use domain names because they are easier to remember. The reality is that those names are in charge of translating them to the DNS servers and then sending us to that IP address. If we put that public IP in the address bar of the browser we can bypass the firewall. Of course, as long as the firewall does not have a blacklist of IP addresses that cannot be accessed or does traffic inspection. A web page that we can use to find out that IP is WhatIsMyIPAddress.

This form of connection will only work in cases where the firewall blocks traffic at the DNS level. However, if the blocking is through DNS and IP, it will not work because it will also detect that we are connecting to unauthorized websites. If you cannot use Proxy and VPN to attempt to bypass firewalls, this trick might work well for you to connect without limitations. However, you will have to know in advance all the IP addresses of the websites you want to access, so it will be quite cumbersome.

Uses DNS over HTTPS

The DOH protocol allows DNS requests and responses to be made through the HTTPS protocol in a fully encrypted manner. If your firewall is blocking access to the Internet through DNS, if you use DOH in the web browser, you will be able to bypass the firewall easily and simply. This is because blocking this protocol is really complicated. Indeed, you would have to block HTTPS accesses to all DNS servers that support this protocol, including Google, so as a general rule this is not blocked.

This DOH protocol is already found in major web browsers such as Chrome or Firefox. It is even present in Microsoft systems. Consequently, it would be advisable to check your DNS settings over HTTPS if you can because this way you could bypass the DNS blocking. Okay, so we have seen how to bypass a firewall. We hope you will use this guide to avoid limitations in your work or school. See you soon.

- Advertisement -
Everything Linux, A.I, IT News, DataOps, Open Source and more delivered right to you.
"The best Linux newsletter on the web"


Please enter your comment!
Please enter your name here

Latest article