Some of the most critical systems in your infrastructure are also the oldest. If you operate in energy, manufacturing, or government, chances are you have hosts still running Red Hat Enterprise Linux 5 or CentOS 5. Not because anyone forgot to upgrade them, but because upgrading them is not an option. The OS is frozen by compliance requirements, tied to certified industrial equipment, or locked to software that would break on anything newer.

You can centralize logs from firewalls, switches, and Linux hosts with a free syslog server - rsyslog, syslog-ng OSE, and the free plan of NXLog Platform all do the job. The real differences show up in Windows support, secure transport, viewers, and what happens when your environment grows. A firewall, a switch, or an auditor says "send your logs somewhere," and there’s no budget line for it. A free syslog server solves the immediate problem in an afternoon.

Your firewalls already record allowed and denied connections and policy changes. Each vendor logs them in its own format. This post shows you how to get those records into one searchable structure, with working configurations for the most common sources. A firewall log analyzer is a tool that collects logs from firewalls, parses each vendor’s log format into structured fields, and stores the results in one place for searching, alerting, and reporting.

Server log analysis turns the raw event records your Windows and Linux servers already produce into security detections, audit evidence, and troubleshooting answers. NXLog Agent and NXLog Platform provide that pipeline: collection and parsing at the source, centralized storage and search on top. Every server you run writes down what happens to it: who logged in, which services started, what the web server returned, why a process crashed. Attackers know this too.

Sysmon fills the visibility gaps that default Windows auditing leaves open — but only if you collect the right event IDs. Here’s the complete event ID reference, my recommended collection tiers for threat detection, and working configurations for getting Sysmon data off the endpoint with NXLog Agent. Sysmon (System Monitor) is a free Microsoft tool — a Windows system service and device driver — that logs detailed system activity, such as process creation, network connections, and registry changes, to the Windows Event Log.

When a cloud region goes down, most teams think about their applications first. But if your log management platform goes dark, you lose more than a dashboard — you lose your audit trail, your security telemetry, and in many industries, your compliance posture. Every minute your ingestion endpoint is unreachable is a minute of blind spots you can’t get back. The good news: if you run NXLog Platform on AWS, building a multi-region disaster recovery (DR) setup is more straightforward than you might expect.