Cabletron Systems CSX100 series User Manual - Enable Nat

ISDN Router

72

Network Address Translation (NAT)

NAT is an IP address conversion feature that translates a PC’s local (internal)

address into a temporary global (outside/Internet) IP address.

NAT is needed when a PC (or several PCs) on a Local Area Network wants to

connect to the outside Internet to get to a remote network: NAT swaps the

local IP address to a global IP address. Our version of NAT goes one step

further by allowing several PCs to share one single IP address to the Internet,

thus reducing connection costs. In effect, it allows a whole LAN to connect to

the Internet as a Single User.

Enable NAT

Important:  Make sure that IP routing is enabled.

⇒

 From the Configuration Manager’s main menu, click Remote Routers

and then TCP/IP Route Addresses.

⇒

 In the TCP/IP Routes window, check the Enable Address Translation

box.

Source and Remote WAN Port Address

This information is required if you are running NAT and the remote router

does not dynamically assign the local/target router WAN Port Address. This

address corresponds to the global IP address and is obtained from your

Network Service Provider.

Most users do not need them as the router can automatically handle the

numbered and unnumbered modes of IP address negotiation.

⇒

 In the TCP/IP Routes window, click Advanced.

⇒

 In the Source WAN Port Address window, enter the IP Address and its

corresponding Subnet Mask and click OK.

Note: For information on WAN RIP settings, refer to the next topic, Routing

Information Protocol.