Linux iptables

Overview

Linux iptables에 대한 기술 문서입니다.

Summary

• 무엇인가? - Linux iptables
• 왜 필요한가? - HPC 및 서버 환경에서 필수 개념
• 언제 사용하는가? - 서버 구성, 성능 튜닝, 문제 해결 시

Purpose

이 문서가 존재하는 이유

• Goal: Linux iptables에 대한 기술 정보 제공
• Scope: Linux iptables의 개념, 사용법, 설정
• Non-goals: 다른 주제로의 확장

Key Concepts

Concept	Description	Related
Linux iptables	HPC/서버 환경에서 중요한 기술 개념	Linux, Server

Detailed Explanation

Among big topic of networking, iptables is incredibly versatile and widely used despite being replaced by nftables on Linux. Iptables works as a command-line firewall that filters packets according to the defined rules. With Iptables, users can accept, refuse, or onward connections.

• TARGET: A target is an action you want Iptables to apply when a packet matches a rule.
• CHAIN: A chain is a list of rules; available built-in chains are: INPUT, OUTPUT, FORWARD, PREROUTING, and POSTROUTING.
• TABLE: Tables are iptables features for each purpose, available tables are filter, nat, raw, security, and mangle. Each table contains rule chains and they are using for routing tasks and another table for filtering tasks.

The following list shows what chains include each table

FILTER	INPUT	OUTPUT	FORWARD
NAT	PREROUTING	POSTROUTING	OUTPUT

Best Practices

• 최신 버전 사용 권장
• 공식 문서 참고
• 테스트 환경에서 먼저 검증

References

• Linux iptables

Related Pages

• Linux
• Server
• Hardware
• Network

Knowledge Graph

Related

→ Linux Kernel Tuning → systemd → LVM → iptables → Ubuntu → fstab → Linux Kernel