Cisco Systems 3750E Manual De Usuario

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Catalyst 3750-E and 3560-E Switch Software Configuration Guide

OL-9775-02

Chapter 1 Overview

Features

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Trusted boundary for detecting the presence of a Cisco IP Phone, trusting the CoS value
received, and ensuring port security

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Policing

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Traffic-policing policies on the switch port for managing how much of the port bandwidth
should be allocated to a specific traffic flow

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If you configure multiple class maps for a hierarchical policy map, each class map can be
associated with its own port-level (second-level) policy map. Each second-level policy map can
have a different policer.

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Aggregate policing for policing traffic flows in aggregate to restrict specific applications or
traffic flows to metered, predefined rates

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Out-of-Profile

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Out-of-profile markdown for packets that exceed bandwidth utilization limits

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Ingress queueing and scheduling

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Two configurable ingress queues for user traffic (one queue can be the priority queue)

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Weighted tail drop (WTD) as the congestion-avoidance mechanism for managing the queue
lengths and providing drop precedences for different traffic classifications

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Shaped round robin (SRR) as the scheduling service for specifying the rate at which packets are
sent to the stack or internal ring (sharing is the only supported mode on ingress queues)

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Egress queues and scheduling

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Four egress queues per port

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WTD as the congestion-avoidance mechanism for managing the queue lengths and providing
drop precedences for different traffic classifications

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SRR as the scheduling service for specifying the rate at which packets are dequeued to the
egress interface (shaping or sharing is supported on egress queues). Shaped egress queues are
guaranteed but limited to using a share of port bandwidth. Shared egress queues are also
guaranteed a configured share of bandwidth, but can use more than the guarantee if other queues
become empty and do not use their share of the bandwidth.

Layer 3 Features

These are the Layer 3 features:

Note

Some features noted in this section are available only in the IP services feature set.

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HSRP for Layer 3 router redundancy

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IP routing protocols for load balancing and for constructing scalable, routed backbones:

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RIP Versions 1 and 2

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OSPF (requires the IP services feature set)

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Enhanced IGRP (EIGRP) (requires the IP services feature set)

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Border Gateway Protocol (BGP) Version 4 (requires the IP services feature set)

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IP routing between VLANs (inter-VLAN routing) for full Layer 3 routing between two or more
VLANs, allowing each VLAN to maintain its own autonomous data-link domain