An iptables syntax quick reference

Taking a look at what you have

iptables -L [chain] - Lists your current iptables configuration

Making modifications

iptables -A [chain] - Append a rule to a desired chain in the current configuration

iptables -D [chain] - Delete a rule from a desired chain in the current configuration

iptables -R [chain] - Replace an existing rule from a desired chain in the current configuration

iptables - I [chain] - (that's a capital I as in Insert) Insert a new rule into a desired chain of the current configuration

iptables -N [chain] - Create a new chain

iptables -X [chain] - Delete a chain

Getting rid of all rules and starting over

iptable -X - Delete all chains

iptables -F - Flush the table of all contents

Importing & Exporting

iptables-save > filename - exports the current iptables configuration to a flat file.

iptables-restore < filename - imports an iptables configuration from a flat file and overwrites the current configuration.