The Importance of Firewall Logs

What are Firewall Logs?

Firewall logs are highly descriptive records created by a firewall that contains information regarding the network traffic passing through the device. They usually contain information about the connections allowed and denied by a firewall, including the source and destination IP addresses, port numbers, protocols, and time of the connection attempt.

Firewall logs enable an administrator to monitor and analyze the traffic activity within the network, detect and respond to security threats, and troubleshoot issues with network connectivity. Through their review, organizations will recognize unauthorized access attempts and suspicious behavior, guaranteeing that all security policies are enforced while network infrastructure health is maintained.

Types of Firewall Logs

Firewalls generate an array of different log types so it can be challenging to know which logs are important to focus on. So, we’ve listed the best firewall logs to monitor for effect firewall log management.

• Traffic Logs: These logs provide an insight into the network connections, meaning the source/destination IP, source/destination ports, and protocols. These logs help in determining non-authorized or questionable traffic.

• Threat Logs: These make evident security threats, for instance, malware, intrusion trials, or denied connections. Monitoring the threat logs will help in the detection of the potential risks.

• URL Filtering Logs: Tracks web traffic and accessed URLs. It is helpful for web usage policy enforcement and in detecting malicious sites.

• Authentication Logs: Observe authentication events between users. Identify unsuccessful authentications or suspicious activities.

• Config logs: Monitor changes in configuration. Some changes can cause security breaches.

Why You Should Monitor Firewall Logs

Monitoring firewall logs offers numerous advantages that highlight why you should monitor these logs. Firstly, firewall logs can help you to understand the patterns of network traffic and also to identify anomalies. Monitoring trends in the logs can assist administrators in recognizing unusual spikes in traffic volume, unusual connection attempts, or patterns of behavior that are not typical. Such anomalies may indicate security incidents such as DoS attacks, port scanning, or attempts to penetrate the network infrastructure.

Also, these particular logs are used to preserve the security and integrity of the infrastructure in a network. First of all, firewall logs keep a detailed record of incoming and outgoing traffic in the network in terms of allowed or blocked connections. Continuous monitoring of the logs will enable the administrator to identify and analyze network activity patterns to know if there could be any potential security threats, like unauthorized access attempts, malware infections, or suspicious behavior.

As well as this firewall log monitoring helps to comply with regulatory requirements and industry standards. Many of the existing regulations, like the Payment Card Industry Data Security Standard (PCI DSS), and the Health Insurance Portability and Accountability Act (HIPAA), require the organization to keep detailed logs of all network activities for review and/or audits. Regular monitoring of firewall logs guarantees that organizations will be able to support the needed evidence of compliance during auditing and inspection activities.

Lastly, firewall logs can be used to serve forensic purposes in case there is a security incident. Through log analysis, it becomes easy for a company to reconstruct what happened in the progress of time before the security was breached, thus determining the root cause of the incident and putting in place remediation measures to rectify such a situation. Forensic analysis will also enable organizations to reduce the impact of security breaches and associated risks and ultimately enhance their security posture.

Firewall Log Management: Best Practices

For effective monitoring of firewall logs, firewall log management is commonly used. Firewall log management is the process of collecting, analyzing, and securely storing logs generated by firewall devices deployed within an organization's network infrastructure. This practice can be challenging so to ensure you maximize its benefits we’ve listed the best practices of firewall log management.

Firstly, a good best practice is to ensure comprehensive logging by enabling any available detailed logging facilities on the firewall. This can involve logging all the traffic, whether inbound or outbound, in addition to capturing important events, such as blocked attempts, suspicious activities, and configuration changes. This enables the organization to allow extensive logging to achieve visibility into their network activities, which is critical for identifying potential threats and understanding normal versus abnormal traffic patterns.

Another best practice is the centralized collection and storage of firewall logs. A centralized logging server gathers the logs from many firewalls and other network devices into a single location. This centralized approach allows for easier analysis and correlation of events, along with long-term storage, which is important for compliance with regulatory requirements and conducting thorough forensic investigations when security incidents occur.

Lastly, firewall log reviews and analysis should be regularly conducted. Organizations need to create a review schedule that can, many times, be automated with the use of scripts or special tools. Regular analysis helps to identify trends, detect anomalies, and further reveal security incidents that might have escaped notice under other circumstances. Moreover, alerting mechanisms for critical events will offer the capabilities to get real-time notification of prospective security issues so that actions are expedited and mitigated.

If you've enjoyed this article why not read Why Are Firewalls Important for Cybersecurity or How Log Management Underpins the Internet of Things (IoT) next?