Linux Networking: systemd-networkd, IPv6, nftables, and Load Balancer Configuration
Executive Summary Networking baseline = reliable, secure, predictable connectivity with proper tuning for your infrastructure.
Why networking configuration matters:
Most production outages trace back to network issues: misconfigured firewall blocking traffic, exhausted connection tables, or timeouts set too aggressively. Proper networking prevents these disasters.
Real-world disasters prevented by good networking:
1. Firewall accidentally blocks production traffic:
Problem: Engineer adds SSH rule, accidentally sets policy to "drop all" Result: Website goes down, SSH also blocked (can't fix it remotely) Prevention: Test firewall rules with policy "accept" first, then switch to "drop" 2. Connection tracking table exhausted:
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