Cisco 3845 - Security Bundle Router Software Guide

1-5
Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 1 Overview
Features
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 faults
• IEEE 802.1D Spanning Tree Protocol (STP) for redundant backbone connections and loop-free
networks. 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) 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 transitioning root and
designated ports to the forwarding state
• Optional spanning-tree features available in PVST+, rapid-PVST+, and MSTP modes:
– Port Fast for eliminating the forwarding delay by enabling a spanning-tree port to immediately
transition from the blocking state to the forwarding state
– Bridge protocol data unit (BPDU) guard for shutting down Port Fast-enabled ports that receive
BPDUs
– BPDU filtering for preventing a Port Fast-enabled ports 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
• Flex Link Layer 2 interfaces to back up one another as an alternative to STP for basic link
redundancy in a nonloop network with preemptive switchover and bidirectional fast convergence,
also referred to as the MAC address-table move update feature
• Flex Link Multicast Fast Convergence to reduce the multicast traffic convergence time after a Flex
Link failure
• Support for Resilient Ethernet Protocol (REP) for improved convergence times and network loop
prevention without the use of spanning tree
• Support for REP edge ports with the no-neighbor option when the neighbor port is not REP-capable
• HSRP for Layer 3 router redundancy
• Equal-cost routing for link-level and switch-level redundancy (requires metro IP access image)
VLAN Features
• Support for up to 4094 VLANs for assigning users to VLANs associated with appropriate network
resources, traffic patterns, and bandwidth
• Support for VLAN IDs in the full 1 to 4094 range allowed by the IEEE 802.1Q standard

Cisco 3845 - Security Bundle Router Specifications

General

Brand	Cisco
Model	3845 - Security Bundle Router
Category	Switch
Language	English