The invention discloses a method for communication between
intranet equipment and internet equipment and NAT (
Network Address Transformation) equipment. The method comprises the steps of: classifying an interface connected with first
intranet equipment and a
public network interface of the NAT equipment per se into a same VLAN (Virtual
Local Area Network) by the NAT equipment, classifying an interface connected with second
intranet equipment of the NAT equipment per se into the other VLAN by the NAT equipment, issuing a
public network IP (
Internet Protocol) address and a
gateway address, distributed to the first intranet equipment, on a virtual interface enabled by the NAT equipment per se, and setting ARP (
Address Resolution Protocol) information of the
IP address to be a silent state; forwarding a received message sent by the first intranet equipment to
the internet from a
public network interface located in the same VLAN with an ingress interface of the message; forwarding a message, which is sent by the second intranet equipment to
the internet and transformed by a
network address port, from the public
network interface; and forwarding a message sent by
the internet equipment according to whether the message is matched with a NAT forwarding table. By applying the method and the NAT equipment, provided by the invention, one equipment in a
local area network can interact with a public network rapidly by using the public network
IP address, and other equipment in the
local area network interact with the public network through NAT.