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Catalyst 2950 Desktop Switch Software Configuration Guide
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Ch apter 1 Overview
Netwo rk Configuration Ex am ples

Multidwelling Network Usi ng Catalyst 2950 Switches

A growing segment of residential and commercial customers are requiring high-speed access to Ethernet
metropolita n-area networks (MANs). Figure 1-6 shows a config uration f or a Gigabit Et hernet MAN r ing
using Catalyst 3550 multilayer switches as aggregation switches in the mini-point-of-presence (POP)
location. T hese swi tch es ar e conn ect ed t hr ough 1 000 BASE-X GBIC po rts.
The resident switches can be Catalyst 2950 switches, providing customers with high-speed connections
to the MAN. C atalyst L RE Lay er 2 o nl y switches also can be us ed as resident i al s witches f o r cu s tom er s
requiring connectivity through existing telephone lines. The Catalyst LRE switches can then be
connect ed to another residen tial switch or to an ag gregati on switch. For more information a bout the LRE
switche s, refe r to the Catalyst 2950 Series Hardware Installation Guide.
All ports on the residential Catalyst 2950 switches (and Catalyst LRE switches if they are included) are
configured as 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 subs criber s. STP root gua rd prevents unauthori zed devices from
becoming t he ST P root switch. Al l po rts h ave IGMP sn oop ing or CGM P ena bled for mu ltic ast tra ffic
management. ACLs on the uplink ports to the aggregating Catalyst 3550 multilayer switches provide
security and bandwidth management.
The aggregating switches and routers provide services such as those described in the pre vious examples,
“Small to Medi um-Sized Networ k Configuration” and “L arge Camp us Configuratio n.”