Cisco 3032 - Availability and Redundancy Features

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Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
OL-12247-04
Chapter 1 Overview
Features
Availability and Redundancy Features
These are the availability and redundancy features:
• HSRP for command switch and Layer 3 router redundancy
• Automatic stack master re-election (failover support) for replacing stack masters that become
unavailable (only stacking-capable switches)
The newly elected stack master begins accepting Layer 2 traffic in less than 1 second and Layer 3
traffic between 3 to 5 seconds.
• Cross-stack EtherChannel for providing redundant links across the switch stack (only
stacking-capable switches)
• 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
– Per-VLAN spanning-tree plus (PVST+) for load-balancing across VLANs
– Rapid PVST+ for load-balancing across VLANs and providing rapid convergence of
spanning-tree instances
– UplinkFast, cross-stack UplinkFast (only stacking-capable switches), 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 (only
stacking-capable switches)
• 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
the blocking state to the forwarding state
– BPDU guard for shutting down Port Fast-enabled ports that receive bridge protocol data units
(BPDUs)
– BPDU filtering for preventing a Port Fast-enabled port from sending or receiving BPDUs
– Root guard for preventing switches outside the network core from becoming the spanning-tree
root
– Loop guard for preventing alternate or root ports from becoming designated ports because of a
failure that leads to a unidirectional link
• Equal-cost routing for link-level and switch-level redundancy
• Flex Link Layer 2 interfaces to back up one another as an alternative to STP for basic link
redundancy