Network Address Translation is an Internet standard that allows hosts on local area networks to use one set of IP addresss for internal communications adn another set of IP addresses for external communicatons.A LAN that uses NAT is referred as natted network.For NAT to funcion,there should be a NAT gateway in each nattled network.The NAT gateway(NAT router) performs IPaddress rewriting on the way a packet travel from to LAN.

 

 

action (accept | add-dst-to-address-list | add-src-to-address-list | dst-nat | jump | log | masquerade | netmap | passthrough | redirect | return | same | src-nat; default: accept ) -action to undertake if the packet matches the rule

 

* each match with this acton will add a message to the system log

* masquerade - replaces source address of IP packet to an automatically determined by the routing facility IP address