Instruction manual

Chapter 1. Understanding IDSL and the Express 6100/6120
1-6 Express 6100/6120 User Manual 61200176L1-1
fault gateway (recommended for remote applications when there are
no other routers on the remote LAN).
IPX Routing
Network routes and services are learned and advertised using Nov-
ell’s RIP and SAP.
Concurrent Routing And Bridging
TheExpress6100/6120canrouteIP and IPX as well asbridge non-IP/
IPX packets simultaneously. The PPPprofile will by default negotiate
PPP network protocols to support the transmission and reception of
IP,IPX,andBridge packets. IfthePPPpeerdoesnotaccept a protocol,
theExpress6100/6120willfallbacktoanycombinationofroutingand
bridging.
Network Address Translation Mode
NAT is a special mode of operation in which the Express 6100/6120
obtains a dynamically assigned IP address from the peer router (typi-
cally an Internet Service Provider). This allows a network of comput-
ers to appear as a single IP address.
NAT is enabled if the layer-two protocol is PPP and the PPP profile
hastheIPparameterNAT settoYes,orthelayertwoprotocolisFrame
Relay and a DLCI mapping has theIP Map/Nat parameter set toYes.
The network computer’s IP stack may use DHCP to request an IP ad-
dress, default gateway address, and domain name server addresses
from the Express 6100/6120.