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Catalyst2950 and Catalyst2955 Switch Software Configuration Guide
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Chapter1 Overview Network Configuration Examples
Figure 1-1 shows configuration examples of using the Catalyst switches to create these networks:
•Cost-effective wiring closet—A cost-effective way to connect many users to the wiring closet is to
connect up to nine Catalyst 2900 XL, Catalyst 2950, Catalyst 3500 XL, and Catalyst 3550 switches
through GigaStack GBIC connections. When you use a stack of Catalyst 295 0G-48 sw itch es, y ou
can connect up to 432users. To preserve switch connectivity if one switch in the stack fails, connect
the bottom switch to the top switch to create a GigaStack loopback, and enable cross-stack
UplinkFast on the cross-stack Gigabit uplinks.
You can create backup paths by using FastEthe rnet, Gigabit, Fast EtherChanne l, or Gigab it
EtherChannel links. Using Gigabit modules on two of the switches, you can have redundant uplink
connections to a Gigabit backbone switch such as the Cataly st 3550- 12G s witc h. If o ne of t he
redundant connections fails, the other can serve as a backup path. You can configure the stack
members and the Catalyst 3550-12G switch as a switch cluster to manage them through a single IP
address.
•High-performance workgroup—For users who require high-speed access to network resources, use
Gigabit modules to connect the switches directly to a backbone switch in a star configuration. Ea ch
switch in this configuration provides users with a dedicated 1-Gbps connection to network resources
in the backbone. Compare this with the switches in a GigaStack configuration, where the 1-Gbps
connection is shared among the switches. With the high speed uplink to the distribution server, the
user can efficiently obtain and store data from servers. Using these Gi gabi t E ther net modul es al so
provides flexibility in media and distance options:
–
1000BASE-T GBIC: copper connections of up to 328 feet (100 mete rs)
–
1000BASE-SX GBIC: fiber connections of up to 1804 feet (550 meters)
–
1000BASE-LX/LH GBIC: fiber connections of up to 32,808 feet (10 kilometers)
–
1000BASE-ZX GBIC: fiber connections of up to 328,084 feet (100 kilometers)
Table1-4 Providing Network Services
Network Demands Suggested Design Methods
High demand for multimedia support •Use IGMP and MVR to efficiently forward multicast traffic.
High demand for protecting mission-critical
applications •Use VLANs and protected ports to provide security and port isolation.
•Use VLAN trunks, cross-stack UplinkFast, and BackboneFast for
traffic-load balancing on the uplink ports so that the uplink port with a
lower relative port cost is selected to carry the VLAN traffic.
An evolving demand for IP telephony •Use QoS to prioritize applications such as IP telephony during
congestion and to help control both delay and jitter within the network.
•Use switches that support at least two queues per port to priorit ize vo ice
and data traffic as either high- or low-priority, based on 802.1p or
802.1Q.
A growing demand for using existing
infrastructure to transport data and voice from
a home or office to the Internet or an intranet at
higher speeds
•Use the Catalyst 2900LRE XL or Catalyst 2950 LRE switches to
provide up to 15Mb of IP connectivity over existing infrastructure
(existing telephone lines).