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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter1 Overview
Network Configuration Examples
Multidwelling Network Using Catalyst 3750 Switches
A growing segment of residential and commercial customers are requiring high-speed access to Ethernet
metropolitan-area networks (MANs). Figure1-8 shows a configuration for a Gigabit Ethernet MAN ring
using multilayer switch stacks as aggregation switches in the mini-point-of-presence (POP) location.
These switches are connected through 1000BASE-X SFP module ports.
The resident switches can be Catalyst 3750 switches, providing customers with high-speed connections
to the MAN. Catalyst 2900 LRE XL and Catalyst 2950 LRE switches also can be used as residential
switches for customers requiring connectivity through existing phone lines. The Catalyst2900 LRE XL
and Catalyst 2950 LRE switches can then connect to another residential switch or to a Catalyst 3750
aggregation switch. For more information about the Catalyst Long-Reach Ethernet (LRE) switches, see
the documentation sets specific to these switches for LRE information.
All ports on the residential Catalyst 3750 switches (and Catalyst 2950 LRE switches if they are included)
are configured as IEEE 802.1Q trunks with protected port and STP root guard features enabled. The
protected port feature provides security and isolation between ports on the switch, ensuring that
subscribers cannot view packets destined for other subscribers. STP root guard prevents unauthorized
devices from becoming the STP root switch. All ports have IGMP snooping or CGMP enabled for
multicast traffic management. ACLs on the uplink ports to the aggregating Catalyst3750 multilayer
switches provide security and bandwidth management.
The aggregating switches and routers provide services such as those described in the examples in the
“Small to Medium-Sized Network Using Catalyst 3750 Switches” section on page 1-25 and the “Large
Network Using Catalyst 3750 Switches” section on page1-26.