Applications
28
Should You Bridge or Route?
When connecting two Local Area Networks together, the first question
to ask is should I bridge or route? The decision to bridge or to route
may be decided by how the existing networks have been already set up.
Bridging should be used when the network consists of non-routable
protocols or routable protocols using the same network numbers.
Some protocols can only be bridged; some of the more well known are
NetBEUI (used by Microsoft Windows 3.11, Windows ’95 and
Windows NT), and LAT (used by Digital Equipment Corp.).
If your IPX or IP network address is the same at both locations
bridging is simpler and requires less configuration. If the locations are
to be routed together, the network numbers will have to be different in
both cases, this could require extensive reconfiguration.
IPX routing should be used if the two locations are already set up with
different IPX network numbers. Routing IPX will minimize the
number of SAP and RIP messages being sent across the WAN.
IP routing should be used if the two locations are already set up with
different IP network numbers or if you wish to divide your one IP
network number into two sub-networks.
In some cases both bridging and routing may be required. Routing
may be required for IP information and bridging may be required for
NetBEUI.