Category Archives: Web Filtering

egress filtering

What Is Egress Filtering?

Egress Filtering is said to be a preventive measure which controls the internal resources from making unauthorized access. It ensures that the sites which are accessible are only trusted sites. It does not just save your internal resources, but it is also helpful in decreasing the threat that our digital services have. As interacting with an infectious entity may cause damage to your server. That is why egress filtering helps in controlling and regulating any kind of data which is related to an external entity. Egress Filtering acts as a firewall. Before any outbound connection is made or is allowed, it requires to pass through the set of rules. The administrator sets these rules and filters. In other words, egress filtering is also known as outbound filtering, as it helps in keeping all the outbound infectious entities away.

It is always said that if you want to keep your server or internal resources safe, then make sure that you use the egress filtering. People may feel that egress filtering is not something very important. But they need to understand, that egress filtering is equally important in all the organizations. If you consider the safety and security of your data, your server, and other internal resources, very important, then you must use the egress filtering.

Some people disable the egress filtering by mistake and are unaware of it. But in most of the cases, the egress filtering is default disabled. And this is also one of the reasons why people are not much aware of egress filtering. Let’s get some more details related to the egress filtering.

Some Of The Best Practices of Egress Filtering

If you want to bring the egress filtering in use, there are some egress filtering practices which you need to follow.

egress filtering best practices

Review the sensitive networks and security zone – No matter which network you are using, as almost every network has some or the other network segments which are very sensitive. These network segments are not accessible directly. These networks have PCI zone or DMZ zone and are very important for the data entry and network, as they work as a firewall for them. That is why it is important to manage, review, and audit these firewalls or security zones just like any other firewall. There should be no gap in between their review and the same frequency for reviewing them should be allowed.

Outbound Firewall rules need to provide business justification – This means if there are any kind of outbound firewall rules or policies created, the complete business justification should also be mentioned with it. It should include everything like Why these policies were made, who will use these policies, the name of the systems or the application that manage the use of these policies, and many other such things. This will help you in knowing the exact reason behind your firewall rules. It will also help in auditing the firewall rules properly.

If possible, try to use a proxy – Using a proxy helps in limiting the traffic that is reaching the firewall. As your firewall will be able to accept only a few proxies, and that is why only limited traffic gets accepted by the firewall. That is why it is recommended to make use of proxy, as it will help in securing the outgoing traffic also.

These are some of the ways, you can practice the egress filtering. It will help in providing security to your network and servers.

Where one should use the egress filter

egress filtering firewall

The egress filter should be deployed at the network’s edge. Most of the firewalls which are for the security of the network are placed here only. As we already mentioned above that in egress filtering everything which is there on the network needs to pass through it. So, that the firewall can check any infectious entity.

Why make use of the Egress Filtering

As we now already know, what egress filtering is and how important it is for us. We also need to know why to make use of the Egress Filtering. Just because it does not cater to all the security needs doesn’t mean that it is not very important. Unfortunately there are a lot of people with malicious intentions looking to exploit vulnerable people that are active on the internet. There are many ways that these malicious actors attempt to exploit security vulnerabilities. They go through email, networks and target specific content. One such area that receives a lot of focus is adult sites. Scammers and hackers know that users accessing porn sites and adult dating sites are not always vigilant or secure. While sex sites like advise their fuckbuddy seeking members about online safety, most adult dating apps don’t offer information about security to their members, let alone egress filtering. The reality is, is this is a large corner of the internet and security and privacy should be prioritized. Knowing about why to make use of the egress filtering, will also help us in understanding its importance in a better way.

  • Helps in blocking the unwanted services – There are many types of unwanted service available on the internet these days. If the users do not want to make use of any of these unwanted services, the egress filter is very helpful in doing that. It blocks the protocols and ports so that one cannot access those services. Like if there is any gaming site or service on the internet and if you do not want your kid to use it, you can use egress filtering for blocking it or limiting the service.
  • Saves your system from attacks – Egress filtering not just acts as a firewall, but it also good for other things. Like it helps in protecting your system from different attacks like malware hosting, DDoS Attacks, Botnets, and Spamming. It helps in blocking the different types of traffic so that it can save your system from such threats.
  • Helps in Disrupting Malware – If your system is infected with malware, the egress filtering can help in disrupting it. It stops your infected system from getting connected to malware’s command server. Also, the egress filter stops and prevents the malware in exporting any of the internal or machine data to its destination. This helps in saving your system from leakage of any of your digital data which could have been a big loss for you.
  • Helps in making one aware of the network traffic – If you are using the egress filter, it will help you in becoming aware of your network and the unauthorized access or activity on your network. If the machine or the system will try making unauthorized connections, you will get the alerts, with the help of the egress filter.

Filtering Web Traffic Through Proxy Servers

The best way to monitor and filter the kind of web traffic that is going into your IT environment is through the use of proxy server. There are two distinct ways of filtering web traffic using proxy servers which include explicit and transparent web proxy.

What is a proxy server?

A proxy server is a gateway between the internet and the user. By acting as an intermediary between the end user and the browser, proxy servers help to provide varying levels of security, privacy and functionality. For a computer that is using a proxy server, whenever you request an address then it will go through the proxy server first and when the request comes back it will go through the same proxy server before it gets to you. The proxy server acts as a firewall and web filter where it keeps the internal network protected by providing a high level of security.

Mechanism of operation

Every computer that has access to the internet has its own unique internet protocol otherwise known as IP address. You can think of the IP address as your street address where the post office will deliver your mail. The internet operates in a similar manner where it identifies your internet usage in terms of IP address.

A proxy server on the other hand is a computer on the internet that is known by your computer. Any request you send on the web will be directed to the proxy server then the proxy server will send the request on your behalf. Incoming data as well goes through the proxy server before it gets to you. The proxy server can encrypt your IP address and the data that is being transmitted to ensure privacy and protection.

Explicit web proxy

Explicit web proxy entails the IT admin configuring all clients that need to be filtered so that they can use a particular proxy. This is achieved through configuring the internet options of all the computers in the network keeping in mind the varying operating systems that are used across the platform. The IT admin will ensure that there are no other ways to access the internet other than through the proxy server and also ensure that users do not get the privilege to change their internet options.

Explicit web proxy does a great job for web filtering in controlled environments. However, maintaining such a process in the long term is very difficult and time consuming. There are limitations with using this kind of proxy servers like mobile support devices is limited. Only the IT admin can deliver the proxy setting for corporate WiFi.

Transparent web proxy

Transparent proxies function in a very similar manner as the explicit proxies only that they do not need to be configured by an IT admin and doesn’t require every client to pass through the proxy server. This kind of technology can be used on an internet gateway where the IT admin will route web traffic through the proxy server. The function of the proxy server would be to look at the network traffic. Identify the exact http(s) and then without the clients knowledge reply through the proxy server.

There are tremendous benefits with using transparency proxy server in that the web traffic will always be filtered regardless of what the end users do with their machines. It is very cost effective as it reduces the need of having an IT department to monitor internet usage and options. The only limitation with transparency proxy server is authentication. Since the users are left in the dark, browser and web applications will not know that they need to authenticate.

Why use proxy server

There are a lot of reasons why you should use a proxy server. One of the reasons is to control the internet usage of children and employees. Most organizations do not want you to look at certain websites or applications during working hours hence can use a web filter to create those limits. It also comes in handy for parental control against explicit web pages. A good proxy server can also be used to save on bandwidth and improve internet speed in an organization. In addition, privacy and improved security is the primary goal of using proxy servers.