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Catalyst 3560 Switch Software Configuration Guide
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Chapter 1 Overview
Network Configuration Examples
You can use the switches to create the following:
• Cost-effective Gigabit-to-the-desktop for high-performance workgroups (Figure 1-1)—For
high-speed access to network resources, you can use the Cisco Catalyst 3560 switches in the access
layer to provide Gigabit Ethernet to the desktop. To prevent congestion, use QoS DSCP marking
priorities on these switches. For high-speed IP forwarding at the distribution layer, connect the
switches in the access layer to a Gigabit multilayer switch with routing capability, such as a
Catalyst 3750 switch, or to a router.
The first illustration is of an isolated high-performance workgroup, where the Catalyst 3560
switches are connected to Catalyst 3750 switches in the distribution layer. The second illustration is
of a high-performance workgroup in a branch office, where the Catalyst 3560 switches are
connected to a router in the distribution layer.
Each switch in this configuration provides users with a dedicated 1-Gb/s connection to network
resources. Using SFP modules also provides flexibility in media and distance options through
fiber-optic connections.
Tab l e 1-2 Providing Network Services
Network Demands Suggested Design Methods
Efficient bandwidth usage for
multimedia applications and
guaranteed bandwidth for critical
applications
• Use IGMP snooping to efficiently forward multimedia and multicast traffic.
• Use other QoS mechanisms such as packet classification, marking, scheduling,
and congestion avoidance to classify traffic with the appropriate priority level,
thereby providing maximum flexibility and support for mission-critical, unicast,
and multicast and multimedia applications.
• Use optional IP multicast routing to design networks better suited for multicast
traffic.
• Use MVR to continuously send multicast streams in a multicast VLAN but to
isolate the streams from subscriber VLANs for bandwidth and security reasons.
High demand on network redundancy
and availability to provide always on
mission-critical applications
• Use Hot Standby Router Protocol (HSRP) for cluster command switch and router
redundancy.
• Use VLAN trunks 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 prioritize voice and data
traffic as either high- or low-priority, based on IEEE 802.1p/Q. The switch
supports at least four queues per port.
• Use voice VLAN IDs (VVIDs) to provide separate VLANs for voice traffic.
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 Long-Reach Ethernet (LRE) switches to provide up to 15 Mb of IP
connectivity over existing infrastructure, such as existing telephone lines.
Note LRE is the technology used in the Catalyst 2900 LRE XL and Catalyst 2950
LRE switches. See the documentation sets specific to these switches for LRE
information.