Your firewall is one of the most critical lines of defence for your network. While the easiest thing in the world would be to make it absolutely impenetrable; you could lock your legitimate users out in the process.
Thus, one must balance the need of securing the environment, against the convenience of the community of people who are supposed to be able to get past it to conduct business. Moreover, your firewall must be as future proof as possible.
These requirements make optimizing network firewall security something of an art.
Here’s how to go about it.
Set the Default to Block Everyone
Yes, we know this flies in the face of the convenience aspect, however, you must make users prove they’re supposed to be in, lest usurpers figure out a way to piggyback on pre-authorized users.
Moreover, you’ll need to be very selective about defining the group of people who are authorized to reconfigure the firewall. This might seem like common sense, but everything bears repeating when it comes to security.
User access must also be diligently logged, so you have a trail to follow if an incursion is detected. Monitor those logs religiously. Create separate user profiles authorizing tiered access based upon the duties of each position in the IT department.
Plan Configuration Changes
Rather than enacting configuration changes at random, draft a plan outlining the need for the change and provide it to management before conducting the change. To ensure this plan is well defined, it must delineate and justify the nature of the changes.
The risks involved should be enumerated and a plan for mitigating those concerns must be presented. Change management workflow between the network teams should be established and documented. And, as always, the proper audit trail protocols should be followed.
Manage Your Rules Base Carefully
Rules must be both specified and optimized to effect the desired security actions. Look for redundancies and eliminate them where practical. Obsolete and unused rules should be stricken to simplify your network firewall security management.
Non-essential shadowed rules should be eliminated too, as should be rules that conflict with one another. Look also for errors and inaccuracies in the rules and excise them to avoid malfunctions they might cause.
Perform Software Updates Immediately
Security updates are usually issued in response to incidents, or the discovery of a flaw that could permit unauthorized access. Delaying these updates leaves your network vulnerable to those known weaknesses.
With that said, it’s also important to perform due diligence on any issued updates to be certain they came from the vendor and are not, in fact, a hacker trying to “Trojan Horse” your network.
Always verify the veracity of an update performing it.
Audit Your Security Processes Regularly
Regular audits should be performed to be certain your firewall rules remain in compliance with your organizational goals. This helps you to be certain all configuration changes have been authorized and catch any that may have not been.
Even stricter scrutiny should be applied upon the installation of a new firewall, during and after a migration and when bulk configuration changes have been implemented.
Establish Centralized Management
There are instances when multiple firewalls from different vendors might be deployed in a network. This generally introduces architectural differences, which in turn can make firewall management a bit of a challenge.
Management of all of them in one place helps to counter this.
Multi-vendor firewall management tools provide an overarching view of the rules and policies governing each one. These platforms also assist with security auditing and reporting, configuration troubleshooting, and gap analysis support for migration.
These tips for optimizing network firewall security will help ensure your defenses are as robust as possible, while minimally impacting the convenience of your authorized users.