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Cisco ME 3400 EthernetAccess Switch SoftwareConfiguration Guide
78-17058-01
Chapter1 Overview
Features
•Cisco IOS File System (IFS) for providing a single interface to all file systems that the switch uses
•In-band management access for up to 16 simultaneous Telnet connections for multiple CLI-based
sessions over the network
•In-band management access for up to five simultaneous, encrypted Secure Shell ( SSH) connections
for multiple CLI-based sessions over the network (requires the cryptographic versions of th e switch
software).
•In-band management access through SNMP Versions 1, 2c, and 3 get and set requests
•Out-of-band management access through the switch console port to a directly attached terminal or
to a remote terminal through a serial connection or a mo dem
•User-defined command macros for creating custom switch configurations for simplified deployment
across multiple switches
Availability Features
•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 faul ts
•IEEE 802.1D Spanning Tree Protocol (STP) for redundant backbone connections and loop-free
networks (supported only on NNIs). STP has these features:
–
Up to 128 supported spanning-tree instances
–
Per-VLAN spanning-tree plus (PVST+) for balancing load across VLANs
–
Rapid PVST+ for balancing load across VLANs and providing rapid convergence of
spanning-tree instances
•IEEE 802.1s Multiple Spanning Tree Protocol (MSTP) on NNIs 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 immedi ate ly
transitioning root and designated port NNIs to the forwarding stat e
•Optional spanning-tree features available in PVST+, rapid-PVST+, and MSTP m odes on NNI s:
–
Port Fast for eliminating the forwarding delay by enabling an NNI t o im medi ate ly tra nsit ion
from the blocking state to the forwarding state
–
Bridge protocol data unit (BPDU) guard for shutting down Port Fast-enabled NNIs that receive
BPDUs
–
BPDU filtering for preventing a Port Fast-enabled NNI 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 port NNIs from becoming designated ports because
of a failure that leads to a unidirectional link
•Flex Link Layer 2 interfaces to back up one another as an al te rnat ive to STP for ba sic li nk
redundancy in a nonloop network (requires metro IP access or metro access ima ge)
•HSRP for Layer 3 router redundancy (requires metro IP access imag e)
•Equal-cost routing for link-level and switch-level redundancy (requires metro IP access image)