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Drop Invalid Conntrack Early

Firewall (nftables) · easy · solved in-browser (no VM needed) · 3 tiered hints

Write /etc/nftables.conf with a table inet filter and an input chain (type filter hook input). As the first matching behaviour, drop any packet whose conntrack state is invalid (ct state invalid drop) so malformed or out-of-window packets never reach later rules. (Authored config, graded structurally — the engine isn't run here.)

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