Availability And Redundancy Features - Cisco WS-C2960-24LC-S Software Configuration Manual

Features

Availability and Redundancy Features

These are the availability and redundancy features:
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Catalyst 2960 Switch Software Configuration Guide
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Enhanced object tracking, which separates the tracking mechanism from HSRP and creates a
separate, standalone tracking process that can be used by processes other than HSRP
UniDirectional Link Detection (UDLD) and aggressive UDLD 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:
Up to 128 spanning-tree instances supported
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Per-VLAN spanning-tree plus (PVST+) for load balancing across VLANs
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– Rapid PVST+ for load balancing across VLANs and providing rapid convergence of
spanning-tree instances
– UplinkFast and BackboneFast for fast convergence after a spanning-tree topology change and
for achieving load balancing between redundant uplinks, including Gigabit uplinks
IEEE 802.1s Multiple Spanning Tree Protocol (MSTP) for grouping VLANs into a spanning-tree
instance and for providing multiple forwarding paths for data traffic and load balancing and rapid
per-VLAN Spanning-Tree plus (rapid-PVST+) based on the IEEE 802.1w Rapid Spanning Tree
Protocol (RSTP) for rapid convergence of the spanning tree by immediately changing root and
designated ports to the forwarding state
Optional spanning-tree features available in PVST+, rapid-PVST+, and MSTP mode:
Port Fast for eliminating the forwarding delay by enabling a port to immediately change from
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the blocking state to the forwarding state
BPDU guard for shutting down Port Fast-enabled ports that receive bridge protocol data units
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(BPDUs)
BPDU filtering for preventing a Port Fast-enabled port from sending or receiving BPDUs
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Root guard for preventing switches outside the network core from becoming the spanning-tree
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root
Loop guard for preventing alternate or root ports from becoming designated ports because of a
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failure that leads to a unidirectional link
Flex Link Layer 2 interfaces to back up one another as an alternative to STP for basic link
redundancy
Chapter 1 Overview
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