Server Security (Part 2): Protecting Your Server with Firewalls


Welcome to Part 2 of our 4 part series of posts about server security.   As mentioned in our last post, cyber attacks on Internet-connected servers are at an all time high. If you’re not taking steps to actively protect your server, the chances are high that your machine will be compromised. In this QuadraNet blog post, we’ll take a look at what a firewall is and how it can help protect your server safe.

What is a Firewall?

A firewall is defined as “a network security system, either hardware- or software- based, that controls incoming and outgoing network traffic based on a set of rules”.  Servers attached to the Internet frequently deploy a firewall in an attempt to filter out hackers, viruses, and worms from getting through and comprising their system.

Why Use a Firewall?

Firewalls are a critical component to any server configuration. Without this type of network-based filtration, your server is operating with an “Open Door” policy. Virtually any information stored on your machine can be accessed by a hacker and in many cases malicious users can install programs on your server that can often get you in trouble. It’s very common for a hacker to gain access to your system and then install some programs that can send spam, trade illegal files, or launch an attack on another server. In the event that one of these things happens, it will look like you were responsible for this and your server and business can be blacklisted or worse. Another concern is that other types of intrusions can give malicious third parties access to sensitive data belonging to your company or your customers.

How do they work?

Firewall’s filter network traffic based on using a positive control model. This means that the only traffic allowed to pass through the firewall is traffic defined in the firewall policy. The firewall blocks or restricts access to every port except for those that are defined to be publicly available. Doing so minimizes the attackable surface areas of you server thus shrinking you potential vulnerability profile.

How to Setup a Firewall?

On a dedicated server, a firewall is usually installed by default, but don’t let this give you a false sense of security. Each server is different, and it’s in your best interest to have your host or a security professional evaluate your configuration. If you require assistance in this area, please open up a ticket with QuadraNet’s support staff.
In the meantime, watch this video get a general idea of what’s involved and how firewalls work.

Firewalls are a critical element in any server configuration. Even if your services themselves implement security features or restrict themselves to the interfaces you’d like them to run on, a firewall serves as an additional layer of defense.

As you can see, having a firewall on your Internet-connected server is a must.  With proper monitoring and appropriate policy creation, you will be able to give your server an essential layer of defense against hackers and viruses. Both you and you clients will sleep better knowing that you have a firewall protecting your server and its data.