Specifications

18 Chapter 1. Router Concepts
These bridge-only units are pre-configured; no further configuration is required. The unit comes up in bridge
mode automatically.
Upgrading an upgradable bridge to become a router requires the addition of a software option key. The software
option key turns on the IP Routing feature. To read about software option keys, see page 114.
When to Use Routing or Bridging or Both
The following charts describe the operational characteristics of the router when you enable routing, bridging, or
both routing and bridging.
How Routing and Bridging Work Together
The router follows these rules when operating as both a router and a bridge:
¥ The router operates as a router for network protocols that are enabled for routing (IP or IPX).
¥ The router operates as a bridge for protocols that are not supported for routing.
IP/IPX Routing On Bridging to/from Remote Router Off
Data packets carried IP (TCP, UDP), IPX
Operational
characteristics
Basic IP, IPX connectivity
Typical usage When only IP/IPX trafÞc is to be routed and all other trafÞc is to be
ignored. For IP, used for Internet access.
Note: This is the most easily controlled configuration.
IP/IPX Routing On Bridging to/from Remote Router On
Data packets carried IP/IPX routed; all other packets bridged.
Operational
characteristics
IP/IPX routing; allows other protocols, such as NetBEUI (that canÕt be
routed), to be bridged.
Typical usage When only IP/IPX trafÞc is to be routed but some non-routed protocol is
required. Used for client/server conÞgurations.
IP/IPX Routing Off Bridging to/from Remote Router On
Data packets carried All packets bridged.
Operational
characteristics
Allows use of protocols that canÕt be routed (such as NetBEUI).
Typical usage Peer-to-peer bridging and when the remote end supports only bridging.