3Com ADSL Modem Ethernet - Manual (Page 17)

3
M
ANUAL SETUP
This chapter describes how to manually setup the 3Com HomeConnect ADSL
Modem Ethernet.
Configuration
Overview
A bridge connects two or more physical networks together to function as a single,
large network. The 3Com HomeConnect ADSL Modem Ethernet is a learning
bridge. A learning bridge does more than just link networks; it separates network
traffic and forwards only the packets that need to be forwarded.
Bridges separate traffic by examining the Media Access Control (MAC) addresses
contained in data packets. MAC addresses uniquely identify each machine
attached to a network segment. A data packet is not forwarded to another
segment if its destination MAC address resides on the same segment as its source.
To efficiently separate traffic, the bridge maintains a Bridge Forwarding Table. The
table contains a list of MAC addresses and their associated network segments. The
table is built dynamically from the source MAC addresses of data packets passing
through the bridge.
The 3Com HomeConnect ADSL Modem Ethernet bridge supports the Spanning
Tree Protocol (STP). This feature is used when two networks are joined by two
bridges forming a looped network. STP prevents the data packets from circling the
two networks.
The 3Com HomeConnect ADSL Modem Ethernet is a 9-port bridge with a single
ethernet port on the Ethernet physical interface (named eth:1) and 8 ATM PVCs
(WAN ports) through the ATM/ADSL physical interface (named atm:1). Bridge
ports are numbered 1through 9, with the Ethernet port designated as port 1. By
default, packets are not bridged between the WAN ports.
The rest of this chapter provides an overview of the 3Com HomeConnect ADSL
Modem Ethernet basic operations and configuration. The chapter is broken into
the following sections:
■
Bridge Port Management
■
Advanced Bridging
■
IP Access
■
System Administration
Managing Bridge
Ports
Each Bridge WAN Port (2-9) has an associated profile for storing information
about the port. With this profile, you specify ATM Virtual Channel information,
description information and whether the port is currently enabled or disabled.