COMMAND：
       -A, --append chain rule-specification

              Append  one  or  more  rules to the end of the selected chain.  When the source and/or destination names resolve to more than one address, a rule will be added for

              each possible address combination.

       -D, --delete chain rule-specification

       -D, --delete chain rulenum

              Delete one or more rules from the selected chain.  There are two versions of this command: the rule can be specified as a number in the chain (starting  at  1  for

              the first rule) or a rule to match.

       -I, --insert chain [rulenum] rule-specification

              Insert  one  or  more  rules in the selected chain as the given rule number.  So, if the rule number is 1, the rule or rules are inserted at the head of the chain.

              This is also the default if no rule number is specified.

       -R, --replace chain rulenum rule-specification

              Replace a rule in the selected chain.  If the source and/or destination names resolve to multiple addresses, the command will fail.  Rules are numbered starting at

              1.

       -L, --list [chain]

              List all rules in the selected chain.  If no chain is selected, all chains are listed. Like every other iptables command, it applies to the specified table (filter

              is the default), so NAT rules get listed by

               iptables -t nat -n -L

              Please note that it is often used with the -n option, in order to avoid long reverse DNS lookups.  It is legal to specify the -Z (zero) option as  well,  in  which

              case the chain(s) will be atomically listed and zeroed.  The exact output is affected by the other arguments given. The exact rules are suppressed until you use

               iptables -L -v

       -S, --list-rules [chain]

              Print  all  rules  in the selected chain.  If no chain is selected, all chains are printed like iptables-save. Like every other iptables command, it applies to the

              specified table (filter is the default).

       -F, --flush [chain]

              Flush the selected chain (all the chains in the table if none is given).  This is equivalent to deleting all the rules one by one.

       -Z, --zero [chain [rulenum]]

              Zero the packet and byte counters in all chains, or only the given chain, or only the given rule in a chain. It is legal to specify the -L, --list (list) option as

              well, to see the counters immediately before they are cleared. (See above.)

       -N, --new-chain chain

              Create a new user-defined chain by the given name.  There must be no target of that name already.

       -X, --delete-chain [chain]

              Delete  the  optional user-defined chain specified.  There must be no references to the chain.  If there are, you must delete or replace the referring rules before

              the chain can be deleted.  The chain must be empty, i.e. not contain any rules.  If no argument is given, it will attempt to delete every non-builtin chain in  the

              table.

       -P, --policy chain target

              Set  the  policy for the chain to the given target.  See the section TARGETS for the legal targets.  Only built-in (non-user-defined) chains can have policies, and

              neither built-in nor user-defined chains can be policy targets.

       -E, --rename-chain old-chain new-chain

              Rename the user specified chain to the user supplied name.  This is cosmetic, and has no effect on the structure of the table.

PARAMETERS

       The following parameters make up a rule specification (as used in the add, delete, insert, replace and append commands).

       [!] -p, --protocol protocol

              The protocol of the rule or of the packet to check.  The specified protocol can be one of tcp, udp, udplite, icmp, esp, ah, sctp or all, or it  can  be  a  numeric

              value,  representing  one  of these protocols or a different one.  A protocol name from /etc/protocols is also allowed.  A "!" argument before the protocol inverts

              the test.  The number zero is equivalent to all.  Protocol all will match with all protocols and is taken as default when this option is omitted.

       [!] -s, --source address[/mask][,...]

              Source specification. Address can be either a network name, a hostname, a network IP address (with /mask), or a plain IP address. Hostnames will be  resolved  once

              only,  before  the rule is submitted to the kernel.  Please note that specifying any name to be resolved with a remote query such as DNS is a really bad idea.  The

              mask can be either a network mask or a plain number, specifying the number of 1’s at the left side of the network mask.  Thus,  a  mask  of  24  is  equivalent  to

              255.255.255.0.   A  "!" argument before the address specification inverts the sense of the address. The flag --src is an alias for this option.  Multiple addresses

              can be specified, but this will expand to multiple rules (when adding with -A), or will cause multiple rules to be deleted (with -D).

       [!] -d, --destination address[/mask][,...]

              Destination specification.  See the description of the -s (source) flag for a detailed description of the syntax.  The flag --dst is an alias for this option.

       -j, --jump target

              This specifies the target of the rule; i.e., what to do if the packet matches it.  The target can be a user-defined chain (other than the one this rule is in), one

              of  the  special builtin targets which decide the fate of the packet immediately, or an extension (see EXTENSIONS below).  If this option is omitted in a rule (and

              -g is not used), then matching the rule will have no effect on the packet’s fate, but the counters on the rule will be incremented.

       -g, --goto chain

              This specifies that the processing should continue in a user specified chain. Unlike the --jump option return will  not  continue  processing  in  this  chain  but

              instead in the chain that called us via --jump.

       [!] -i, --in-interface name

              Name  of  an  interface via which a packet was received (only for packets entering the INPUT, FORWARD and PREROUTING chains).  When the "!" argument is used before

              the interface name, the sense is inverted.  If the interface name ends in a "+", then any interface which begins with this name will  match.   If  this  option  is

              omitted, any interface name will match.

       [!] -o, --out-interface name

              Name  of  an  interface  via  which  a packet is going to be sent (for packets entering the FORWARD, OUTPUT and POSTROUTING chains).  When the "!" argument is used

              before the interface name, the sense is inverted.  If the interface name ends in a "+", then any interface which begins with this name will match.  If this  option

              is omitted, any interface name will match.

       [!] -f, --fragment

              This  means that the rule only refers to second and further fragments of fragmented packets.  Since there is no way to tell the source or destination ports of such

              a packet (or ICMP type), such a packet will not match any rules which specify them.  When the "!" argument precedes the "-f" flag, the rule will  only  match  head

              fragments, or unfragmented packets.

       -c, --set-counters packets bytes

              This enables the administrator to initialize the packet and byte counters of a rule (during INSERT, APPEND, REPLACE operations).