Chapter 1 Overview
Features
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Catalyst 2900 Series XL and Catalyst 3500 Series XL Software Configuration Guide
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Redundancy
•
HSRP for command switch redundancy
•
UniDirectional link detection (UDLD) on all Ethernet ports for detecting and disabling
unidirectional links on fiber-optic interfaces caused by incorrect fiber-optic wiring or port faults
•
IEEE 802.1d Spanning Tree Protocol (STP) for redundant backbone connections and loop-free
networks. STP has these features
–
Per-VLAN Spanning Tree (PVST) for balancing load across virtual LANs (VLANs)
–
Port Fast mode for eliminating forward delay by enabling a port to immediately change from
a blocking state to a forwarding state
–
UplinkFast, Cross-Stack UplinkFast, and BackboneFast for fast convergence after a
spanning-tree topology change and for achieving load balancing between redundant uplinks,
including Gigabit uplinks and cross-stack Gigabit uplinks
–
STP root guard for preventing switches outside the core of the network from becoming the
STP root
Note
Depending on the model, a switch can support up to 64 or 250 instances of STP (see
Table 8-1 on page 8-3
).
VLAN Support
•
Depending on the switch model, up to 64 or 250 port-based VLANs are supported for assigning
users to VLANs associated with appropriate network resources, traffic patterns, and bandwidth
Note
For information about the maximum number of VLANs supported on each
Catalyst 2900 XL and Catalyst 3500 XL switch, see the
Table 8-1 on page 8-3
.
•
Inter-Switch Link (ISL) and IEEE 802.1Q trunking protocol on all ports for simplified network
moves, adds, and changes; better management and control of broadcast and multicast traffic; and
improved network security by establishing VLAN groups for high-security users and network
resources
•
VLAN Membership Policy Server (VMPS) for dynamic VLAN membership
•
VLAN Trunk Protocol (VTP) pruning for reducing network traffic by restricting flooded traffic
to links destined for stations receiving the traffic
Table 1-1
Features (continued)
