COMODO Firewall: Thick lizard skin keeps the threats away

Most owners of Windows-based computers use the firewall that comes with one of the two scenarios as follows: either they are using a free antivirus with the built-in Windows firewall or a more complex anti-malware program such as an internet security suite that comes with its own firewall. This is not all bad since probably any firewall will be able to offer a basic security layer, but there are superior alternatives.

COMODO Firewall is a free product, but its solid protection features make it one of the highest quality stand-alone firewalls currently available. It was basically designed to ensure preventive protection for your PC, trying to stop threats before they occur, not after.

Installation & Requirements

While you will find plenty of settings to perform inside Comodo Firewall, its installation is rather expeditious. After choosing the program’s language you will be presented with two options: one is enabling COMODO Secure DNS Servers that will setup your system to use COMODO’s DNS servers which were designed to provide a faster and safer web browsing experience than by using the ones provided by your ISP. The other one is enabling the “Cloud Based Behavior Analysis” that means submitting unrecognized applications to COMODO. Both of these options are not compulsory as COMODO Firewall does not rely on them to work. The next and final step you have to configure during the install process is choosing what type of network you are connected to: Home, Work or Public Place.

COMODO Firewall may be powerful but it doesn’t have a negative impact on your system’s performance so it has modest system requirements: the program runs on Windows XP SP2, Vista and 7 and requires 152 MB RAM and 400 MB free disk space.


Looking at COMODO Firewall’s interface makes it hard to believe it’s a free product. The tabbed GUI is clean and very easy to navigate as it provides four different tabs for the program’s main functions.

The Summary displays an overview of the most important information regarding Firewall and Defense+ (COMODO’s Host-based Intrusion Prevention System) that monitors all applications on your system and detects potentially dangerous behavior. As a result in this tab you can see at a glance the number of intrusions blocked by Firewall and Defense+, inbound/outbound connections, a list of all running applications that are currently connected to the Internet (in the Firewall section) and the number of unrecognized files observed/applications running in the Sandbox (in the Defense+ section).

The Firewall tab contains all of the information and settings for the firewall made available by the program. From here you can view detailed lists of firewall events and active connections but also define new trusted/blocked applications, network security policy, create global firewall rules and tweak the firewall behavior settings.

In the Defense+ tab you can see the full list of events, alerts and actions taken by Defense+, the active processes list and edit the trusted files list/unrecognized files list, run applications in the Sandbox (run programs in a “sandbox” area of your system to prevent their access to sensitive system areas), edit the computer security policy and change Defense+ settings.

The More section contains various general options and settings including the program’s Preferences, Update check function and access to COMODO Firewall’s documentation and forums.

Concerning COMODO Firewall’s performance, the program monitors all applications that attempt to establish an Internet connection and compares them with its own safe list containing millions of safe programs. The identified ones are marked as safe and automatically allowed to access the Internet but if the application is not on the list, COMODO Firewall will alert you and wait for you to decide. While in the beginning you can expect to face many notifications, remembering your answer as a permanent rule every time a pop-up appears will save you from a lot of trouble later. Defense+ issues the same type of color-labeled warnings (yellow, orange and red based on the severity threat) as soon as it detects suspicious application behavior.

On a similar note you can also configure the Firewall and Defense+ security levels either from the right-click menu of the system tray icon or in the program’s interface from the Settings menus displayed in the respective tabs.


– Simple installation process with no adware.

– Intuitive and friendly interface organized in tabs.

– Highly configurable firewall.

– Excellent application monitoring function (Defense+) with customizable security level and great detection rates.

– Easy to understand alerts.

– Sandbox function allows you to safely test suspicious applications.

– Parental control option with password protection.


– For some reason COMODO Firewall appears in the Windows “Programs and Features” list under the name of COMODO Internet Security which can be confusing for many users. Also, antivirus files are present in COMODO’s install folder despite the fact that the antivirus component was not installed.

– The large number of Defense+ alerts that force users to make decisions make this program unsuitable for non-technical users.


COMODO Firewall is one of the most reliable products in the related industry, but it does have its fair share of competition. Here are a few other popular free firewall applications capable of delivering a similar level of protection: ZoneAlarm Free Firewall, Windows 7 Firewall Control and Privatefirewall.


COMODO Firewall offers an outstanding level of protection for a free product also matched by its eye-pleasing, intuitive interface. It works well with its default settings, yet it allows pretentious users to tweak their copy of the program. Sadly, the frequent alerts issued by the Defense+ function prompt the user to take action so we do not recommend it to beginners. However, with a small dose of technical knowledge COMODO Firewall can make a great combo with the antivirus application of your choice.