7 Firewall Best Practices for Securing Your Network
Original post from https://backbox.com/7-firewall-best-practices-for-securing-your-network/
A network firewall is your most crucial security tool that must be as robust as it can get. Network firewall configuration can be a challenging task for administrators as they have to strike the perfect balance between security and speed of performance for the users.
Network firewall configuration must not only aim at protecting against external security threats but should also protect from malware that could exfiltrate sensitive data from your network to other locations. It is also important to protect the network from any prospective security threats in the future, rather than only concentrating on existing threats.
For network administrators, here is a list of seven firewall best practices to adopt to secure the network from any existing or potential threat:
1. Block traffic by default and monitor user access
It is advisable to block all traffic to the network by default. Allow only some specific traffic to certain known services. This helps you to have control over who can access your network and prevents any security breaches from occurring.
The firewall being your first layer of protection against threats, must not allow access to anyone and everyone to alter the configuration. User permission control is necessary to ensure that only authorized administrators have access to change firewall configurations. Apart from this, every time an authorized administrator does change any configuration, it must be recorded in the log for audits and compliance. Any unwarranted configuration changes can thus be detected, and configuration restore may be implemented in such a case.
You can also create separate user profiles to provide various levels of access to the IT staff, only as much as needed for a job. Firewall logs must be monitored regularly to detect any unauthorized break-ins to the firewall, from inside or outside the network.
2. Establish a firewall configuration change plan
Your network’s firewall will need to be updated from time to time for various reasons. This is necessary to ensure that the firewall remains strong and capable of protecting against new threats. But it is important to have a change management plan so that the process is smooth and secure. Any unplanned configuration change leaves a loophole in your network’s security.
A well-defined and robust firewall change management plan must include certain basic features:
- It must define the changes that are required and their objectives.
- It should also enlist the risks involved due to the policy changes, their impacts on the network, and a mitigation plan to minimize the risks.
- A well-defined structure of change management workflow between various network teams.
- Proper audit trails that record who made the change, why, and when.
3. Optimize the firewall rules of your network
The firewall rules must be well-defined and optimized to provide the expected protection. Cleaning up your firewall rule base of any kind of unnecessary clutter can have a positive impact on your network security.
Your firewall rule base may have certain redundant elements, duplicates, or bloated unnecessary rules that make the guidelines complicated and less effective. It is important to get rid of such rules to have a clear set of guidelines that can be followed better.
To clean your firewall rule base, you must:
- Eliminate redundant or duplicate rules that slow down the firewall performance as they require the firewall to process more rules in its sequence than necessary.
- Remove the rules that are obsolete or no longer in use. These only make the firewall management more complex, and can even be a threat to network security if not updated.
- Remove shadowed rules that are not essential. These may lead to more critical rules being neglected.
- Conflicting rules must be eliminated.
- Any errors or inaccuracies in the rules must be eliminated as these may result in malfunctions.
4. Update your firewall software regularly
Firewall vendors usually release software updates regularly. These updates address any new potential security threats by making minor changes to the software. It is important to keep updating your firewall software to ensure that your network is secure, and there are no loopholes in the system that could pose a threat to security. You must check from time to time if your firewall software is updated to the latest version.
5. Conduct regular firewall security audits
Security audits are necessary to ensure that the firewall rules comply with the organizational, as well as external security regulations that apply to the network. Unauthorized firewall configuration changes that are a policy violation can cause non-compliance. It is important for administrators and IT security staff to carry out regular security audits to ensure no unauthorized changes have taken place.
This will also keep you updated on the necessary changes made to the firewall and warn you against any potential risks created by these changes. Security audits are most essential when there is a new firewall installed, firewall migration activity happening, or when there are bulk configuration changes made on firewalls.
6. Have a centralized management tool for multi-vendor firewalls
Multi-vendor firewalls are quite common in most organizations. Companies prefer firewalls manufactured by different companies installed in the systems to offer additional layers of security. But the challenge here is that the architecture of firewalls from different manufacturers is usually different.
It is important to manage all your firewalls centrally at one place to ensure they are all functioning properly. Using a multi-vendor firewall management tool allows you to have a unified view of firewall policies and rules, enabling you to compare and manage firewall rules easily. You can also perform security auditing and reporting, troubleshoot configuration issues, and provide support with a gap analysis for firewall migration through this centralized management tool.
7. Automate the process of firewall updating
With improvements in technology, many processes have become faster and easier. It may not always be possible for firewall administrators to constantly check for updates and perform software updates regularly. This leaves the network at risk of security breaches.
To avoid any lapse in updating your firewall, you can automate the process instead. An automated system can be scheduled to check for available updates and implement the updates when they find one. This reduces the need for human intervention and keeps the firewall secure and robust at all times.