Cisco Catalyst 3550 Datasheet page 9

Feature
Resiliency and reliability
Redundancy
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Benefit
• IEEE 802.1w Rapid Spanning Tree (RSTP) takes advantage of point-to-point
wiring and provides rapid convergence of the spanning tree independent of
spanning-tree timers. Reconfiguration of the spanning tree can occur in less
than one second, which is critical for metro networks carrying
mission-critical and delay-sensitive traffic such as enterprise data, voice,
and video.
• IEEE 802.1s Multiple Spanning Tree (MSTP), which uses RSTP for rapid
convergence, enables VLANs to be grouped into a spanning-tree instance,
with each instance having a spanning-tree topology independent of other
spanning-tree instances. This architecture provides for multiple forwarding
paths for data traffic, enables load balancing, and reduces the number of
spanning-tree instances required to support a large number of VLANs.
• Cisco UplinkFast/BackboneFast technologies ensure quick failover recovery,
enhancing overall network stability and reliability.
• Cisco CrossStack UplinkFast (CSUF) technology provides increased
redundancy and network resiliency through fast spanning-tree convergence
(fewer than two seconds) across a stack of switches using GigaStack GBICs
in an independent stack backplane cascaded configuration.
• Redundant stacking connections provide support for a redundant loopback
connection for top and bottom switches in an independent stack backplane
cascaded configuration.
• Bridge protocol data unit (BPDU) guard shuts down Spanning-Tree Protocol
PortFast-enabled interfaces when BPDUs are received to avoid accidental
spanning-tree topology changes.
• Spanning-tree root guard prevents edge devices outside the network
administrator's control from becoming STP root nodes.
• Command switch redundancy enabled in the Cisco Cluster Management
Suite (CMS) Software allows customers to designate a backup command
switch that takes over cluster management functions if the primary
command switch fails.
• Unidirectional link detection (UDLD) detects and disables unidirectional
links on fiber-optic interfaces caused by incorrect fiber-optic wiring or port
faults. Aggressive UDLD allows precautionary disabling of port on
bidirectional links.
• Per-port broadcast, multicast, and unicast storm control prevents faulty
end-stations from degrading overall systems performance.
• Support for (Redundant Power System) 300 (RPS 300) that provides
superior internal power source redundancy for up to six Cisco networking
devices resulting in improved fault tolerance and network uptime.
• Bandwidth aggregation of up to 16 Gbps through Cisco Gigabit
EtherChannel technology and up to 1.6 Gbps through Cisco Fast
EtherChannel technology enhances fault tolerance and offers higher-speed
aggregated bandwidth between switches, to routers and individual servers.
• Supports Cisco HSRP to create redundant failsafe routing topologies.
• IEEE 802.1D Spanning Tree Protocol support for redundant backbone
connections and loop-free networks simplifies network configuration and
improves fault tolerance.
Cisco Systems, Inc.
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