Cisco 2950G 24 Software Configuration Guide - Page 50

Network Configuration Examples Chapter 1 Overview Multidwelling Network Using Catalyst 2950 Switches A growing segment of residential and commercial customers are requiring high-speed access to Ethernet metropolitan-area networks (MANs). Figure 1-6 shows a configuration for a Gigabit Ethernet MAN ring using Catalyst 3550 multilayer switches as aggregation switches in the mini-point-of-presence (POP) location. These switches are connected through 1000BASE-X GBIC ports. The resident switches can be Catalyst 2950 switches, providing customers with high-speed connections to the MAN. Catalyst LRE Layer 2 only switches also can be used as residential switches for customers requiring connectivity through existing telephone lines. The Catalyst LRE switches can then be connected to another residential switch or to an aggregation switch. For more information about the LRE switches, refer 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 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 Catalyst 3550 multilayer switches provide security and bandwidth management. The aggregating switches and routers provide services such as those described in the previous examples, "Small to Medium-Sized Network Configuration" and "Large Campus Configuration." 1-18 Catalyst 2950 Desktop Switch Software Configuration Guide 78-14982-01