modprobe= try to insert modules using this command fragment -f match second or further fragments only exact -x expand numbers (display exact values) line-numbers print line numbers when listing table -t table table to manipulate (default: `filter') numeric -n numeric output of addresses and ports Match when the TCP flags are as specified: Target for rule (may load target extension) Source port (use `:' when specifying range) A '!' argument before the address specification inverts the Specifying the number of 1's at the left side of the network mask. The mask can be either a network mask or a plain number,

new -N chain Create a new user-defined chainĬhange chain name, (moving any references) zero -Z Zero counters in chain or all chains flush -F Delete all rules in chain or all chains list -L List the rules in a chain or all chains Replace rule rulenum (1 = first) in chain Insert in chain as rulenum (default 1=first) delete -D chain Delete matching rule from chainĭelete rule rulenum (1 = first) from chain Iptables -h (print this help information) Commands Iptables -E old-chain-name new-chain-name Iptables - chain rulenum rule-specification Basic Usage iptables - chain rule-specification 9 Firewall blocks DHCP renewal responses.6.11 Reject clients from accessing the router's configuration.6.10 Block all traffic except HTTP HTTPS and FTP.

6.9 Allow HTTP traffic only to specific domain(s).

6.8 Block outgoing SMTP traffic except from specified hosts.

6.7 Block SMTP traffic except to specified hosts.

6.6 Deny access to a specific Outbound IP address with logging.

6.5 Deny access to a specific IP address range with Logging.

6.3 Deny access to a specific IP address.

6.2 Port Forwarding to a specific LAN IP.