A Free Sysadmin Troubleshooting Guide for Server & Network Problems
When infrastructure breaks, the hardest part is rarely fixing it — it is knowing where to look. This troubleshooting toolkit was built to answer the question every engineer asks first: what is actually wrong? Rather than forcing you to remember the exact dig, openssl and curl incantations, it runs the right checks for each class of problem automatically and translates the raw output into plain English. If you have ever searched for how to troubleshoot server problems at two in the morning, this is the shortcut.
Each diagnosis follows the same principle a good sysadmin troubleshooting guide teaches: work from the bottom of the stack upward. A website that will not load might be a DNS problem, a certificate problem, or an application error — and the only way to know is to test each layer in order. That is exactly why this is a genuinely useful free sysadmin troubleshooting tool rather than a single checker: it tests DNS resolution, TLS handshake, HTTP response and timing together, so you see the whole path a request takes.
Website down? Troubleshoot from DNS upward
The most common website down troubleshoot mistake is restarting the web server before confirming the domain even resolves. If DNS returns no A record, the browser never reaches your server and no amount of restarting helps. Our website check confirms resolution first, then validates the SSL certificate, then reads the HTTP status code and measures response time. When people describe server problems how to fix scenarios, the fix is usually revealed the moment you know which layer failed.
Email not working? Check authentication and reputation
An email not working troubleshoot session almost always comes down to four DNS records and one reputation check. MX records decide where mail is delivered; SPF, DKIM and DMARC prove your mail is legitimate; and blacklist status determines whether receiving servers trust your IP at all. Missing any of these is the difference between the inbox and the spam folder. The email diagnosis inspects all of them and tells you precisely which record to add or correct.
SSL, DNS and server diagnostics in one place
Certificate errors, propagation delays and refused connections each have their own dedicated diagnosis. The SSL check reports validity, expiry, chain completeness and negotiated TLS version. The DNS check compares answers across twelve global resolvers so propagation is never a guessing game. The server check tests SSH, HTTP and HTTPS reachability to distinguish a crashed service from a firewall rule. Together they make this one of the most practical network troubleshooting tool online options available, and arguably the best server diagnostic tool free of charge that still explains its findings clearly.
Why guided diagnosis beats a single lookup
Individual lookups answer individual questions, but real incidents rarely have a single cause. Learning how to diagnose network problems means correlating signals — a valid certificate on an unreachable port, a correct A record that has not propagated, an SPF record that authorises the wrong server. By running related checks together and presenting them side by side, the toolkit surfaces those correlations for you. Every check is free, requires no signup, and stores nothing about the domains you test. Pick the problem that matches your symptom above, and let the toolkit do the tedious part so you can get to the fix.