IBM Bridge/ Heritage, User Manual

Page: 47 / 167

4-2 Advanced Configurations
4.1 Add NAT to Classic IP, PPP over ATM or PPP
over Ethernet
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.
[System configuration]
[ISP/DSLAM configuration]
IP address : 192.168.102.3
Subnet mask : 255.255.255.0
Gateway : None
[Local PC 1 configuration]
IP address : 202.1.136.101
Subnet mask : 255.255.255.0
Gateway : 202.1.136.254
[Local PC 8 configuration]
IP address : 202.1.136.108
Subnet mask : 255.255.255.0
Gateway : 202.1.136.254
DSLAM/NSP
Ethernet Port
Ethernet Port
Up-Link
PC 1
202.1.136.101
HUB
PC 8
202.1.136.108