Red Hat ENTERPRISE LINUX 4.5.0 Reference Manual page 355

Command options instruct
allowed per
iptables
written in upper-case characters.
The commands are as follows:
iptables
• — Appends the
-A iptables
to add a rule when rule order in the chain does not matter.
• — Checks a particular rule before adding it to the user-specified chain. This command can
-C
help you construct complicated
and options.
• — Deletes a rule in a particular chain by number (such as
-D
You can also type the entire rule, and
• — Renames a user-defined chain. This does not affect the structure of the table.
-E
• — Flushes the selected chain, which effectively deletes every rule in the the chain. If no
-F
chain is specified, this command flushes every rule from every chain.
• — Provides a list of command structures, as well as a quick summary of command
-h
parameters and options.
• — Inserts a rule in a chain at a point specified by a user-defined integer value. If no
-I
number is specified,
Caution
Be aware when using the
are important for determining which rules apply to which packets.
• — Lists all of the rules in the chain specified after the command. To list all rules in all
-L
chains in the default
syntax should be used to list the rules in a specific chain in a particular table:
iptables -L <chain-name> -t <table-name>
Additional options for the
verbose rule descriptions, are described in
• — Creates a new chain with a user-specified name.
-N
• — Sets the default policy for the specified chain, so that when packets traverse an entire
-P
chain without matching a rule, they are sent on to the specified target, such as ACCEPT or
to perform a specific action. Only one command option is
iptables
command. With the exception of the help command, all commands are
rule to the end of the specified chain. This is the command used
rules by prompting you for additional parameters
iptables
iptables
places the command at the top of the chain.
iptables
or
-A
table, do not specify a chain or table. Otherwise, the following
filter
command option, which provide rule numbers and allow more
-L
for the fifth rule in a chain).
5
deletes the rule in the chain that matches it.
option that the order of the rules within a chain
-I
Section 3.6, "Listing Options".
Command Options
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