#networking
All articles tagged #networking — practical guides from production experience.
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23 posts tagged #networking · page 3 of 3
Check Open Ports in Linux: ss vs netstat Explained
How to check open ports in Linux using ss and netstat — with real troubleshooting scenarios, filtering techniques, and a clear comparison of when to use each tool.
Linux TIME_WAIT Explained: Why It Causes Connection Failures and How to Fix It
Linux TIME_WAIT exhausts ephemeral ports and causes ECONNREFUSED under load — even when your app is healthy. Learn what TIME_WAIT is, how to detect port exhaustion with ss and netstat, and the exact sysctl fixes that resolve it.
NGINX Upstream Keepalive Explained: Why Missing It Causes 502 Errors
Missing keepalive in your NGINX upstream block silently kills connections under load. Here's exactly what keepalive does, how TCP connection reuse works, and the production-ready config that stops 502s before they start.
Docker Networking Demystified: bridge, host, and overlay
The three Docker network modes that matter for production — what they actually do, when to use each, and the gotchas that'll bite you if you pick the wrong one.
Replacing iptables with nftables: A Practical Migration Guide
iptables is showing its age. nftables is the modern replacement — cleaner syntax, better performance, and already the default on most distros. Here's how to migrate.