The parameters are described as follows:
•Name – This is a 12 character, alphanumeric,
•Global Interface – This is the interface corresponding to the Global IP and Range parameters, in the NAT table, to form unique IP address[es], known to the outside (regional or Internet) routers, on this interface.
•Local Interface – This is the interface corresponding to the Local IP and Range parameters, in the NAT table, to form local IP address[es], known only to this interface and the network within.
•Translation Mode – There are five choices, including None if no NAT is desired:
Static NAT – Maps one global IP address to one local IP address. After all global IP addresses are assigned, they will remain static. This option may be necessary for email, web, ftp servers, etc. where static IP addresses are essential for operation.
Dynamic NAT – Maps one global IP address to one local IP address. Global IP addresses will be dynamically reassigned to different local IP addresses if not currently being used. This allows a larger number of users to use a small number of IP addresses.
Static NAPT – One to one mapping of UDP/TCP port numbers to let packets with specific UDP/TCP port numbers enter the local IP domain. The NAPT map table will not age. This option may be necessary for email, web, ftp servers, etc. where static port numbers are essential for operation. Setting the global port number to 0 opens port numbers 1024 to 65535 for the designated local IP address, creating a visible computer. This allows a computer to be freely accessed by other computers on the Internet, which is necessary for some applications to function correctly when using NAPT, including Microsoft NetMeeting, CUSeeMe, etc.
Dynamic NAPT - One to one mapping of UDP/TCP port numbers. The NAPT map table will age. This option allows many hosts to use a single, globally unique IP address, and thus will only be used on outbound packets.
•State – Enables or disables this NAT configuration.
NAT IP Pool Configuration Screen
Now you must select, enter, and configure the NAT IP Pool from the NAT
Configuration submenu, shown below.
Dynamic NAT
This screen (below) is how the NAT IP Pool appears, if Dynamic NAT was chosen for the Translation Mode parameter. Each entry, in this configuration, can be used to map multiple, contiguous global addresses and local addresses to each other.
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