Cisco Systems 3560 사용자 설명서

HSRP for command switch and Layer 3 router redundancy

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

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 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 
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

Link-state tracking to mirror the state of the ports that carry upstream traffic from connected hosts 
and servers, and to allow the failover of the server traffic to an operational link on another Cisco 
Ethernet switch.

Support for up to 1005 VLANs for assigning users to VLANs associated with appropriate network 
resources, traffic patterns, and bandwidth 

Support for VLAN IDs in the 1 to 4094 range as allowed by the IEEE 802.1Q standard

VLAN Query Protocol (VQP) for dynamic VLAN membership