ZyXEL Communications P-128IMH, User Manual, Page: 103 / 191

Prestige 128IMH ISDN Modem/ Router/Hub
Bridge Setup 7-1
Chapter 7
Bridging Setup
This chapter shows you how to configure the bridging parameters of your Prestige.
7.1 Bridging in General
Bridging bases the forwarding decision on the MAC (Media Access Control), or hardware,
address, while routing does it on the network layer (IP or IPX) address. Bridging allows the
Prestige to transport packets of network layer protocols that the Prestige does not route, e.g.,
SNA, from one network to another. The caveat is that, compared to routing, bridging generates
more traffic for the same network layer protocol, and it also demands more CPU cycles and
memory.
For efficiency reason, do not turn on bridging unless you need to support protocols other than IP
and IPX on your network. For IP and IPX, enable the respective routing if you need it; do not
bridge what the Prestige can route.
7.2 Bridge Ethernet Setup
Basically, all non-local packets are bridged to the WAN; however, your Prestige applies special
handling for certain IPX packets to reduce the number of calls, depending on the setting of the
Handle IPX field.