Netfilter

Netfilter handles packet filtering, NAT, and connection tracking via kernel hooks.

List firewall rules

Input:

iptables -L -v -n

Output:

Chain INPUT (policy ACCEPT)
pkts bytes target prot opt in out source destination

Shows configured rules, counters, and default policy.

References:

• https://man7.org/linux/man-pages/man8/iptables.8.html

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