iptables โcheat sheetโ - For your convenience!
General command syntax:
iptables๎๎command
๎
๎CHAIN๎๎options๎๎action๎
๎
Commands:
๎L๎โ๎๎List all currently inserted rules
๎F๎/๎๎๎flush๎โ๎๎Delete all rules currently inserted
๎A๎โ๎๎โAppendโ: add a rule to a specific chain
๎
Chains:
INPUT๎๎๎โ๎๎Chain for packets targeted to your machine
FORWARD๎โ๎๎Chain for packets that your machine will route
OUTPUT๎๎โ๎๎Chain for packets that your machine sends out
๎๎policy๎CHAIN๎DROP/ACCEPT๎โ๎๎Set default behaviour for a chain
๎
Options:
๎d๎/๎๎s๎โ๎๎Filter by destination/source IPs
๎p๎TCP๎โ๎๎Filter TCP packets
๎๎dport๎/๎๎๎sport๎#/name๎โ๎๎Filter by port # (or service, such as http, sshโฆ)
๎๎tcp๎flags๎ALL๎๎FLAG
๎
๎โ๎๎Filter by flag. ๎ALL๎๎means โinspect all packetsโ,
substitute ๎FLAG
๎
๎๎with the flag you want to filter
๎
๎m๎๎MODULE
๎
๎โ๎๎Load an extension (for this lab: ๎string๎/๎state๎)
๎๎string๎๎โpatternโ
๎
๎โ๎๎Match ๎โpatternโ
๎
in packets
๎๎algo๎bm๎โ๎๎Use Boyer-Moore for pattern matching
๎๎state๎๎OPTION
๎
๎โ๎๎Filter by connection state. Can be ๎NEW๎, ๎RELATED๎, ๎ESTABLISHED๎ or
INVALID๎
๎
Actions:
๎j๎DROP/ACCEPT๎โ๎๎Action to take on matched packets๎