Cisco Catalyst 4500 Series Command Reference Guide

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Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.4.0SG and IOS 15.1(2)SG)
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Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
flowcontrol
Usage Guidelines The pause frames are special packets that signal a source to stop sending frames for a specific period of
time because the buffers are full.
Table 2-4 describes the guidelines for using the different configurations of the send and receive
keywords with the flowcontrol command.
Table 2-5 identifies how the flow control will be forced or negotiated on the Gigabit Ethernet interfaces
based on their speed settings.
Examples This example shows how to enable send flow control:
Switch(config-if)# flowcontrol receive on
Switch(config-if)#
This example shows how to disable send flow control:
Switch(config-if)# flowcontrol send off
Switch(config-if)#
Table 2-4 Keyword Configurations for send and receive
Configuration Description
send on Enables a local port to send pause frames to remote ports. To obtain
predictable results, use send on only when remote ports are set to
receive on or receive desired.
send off Prevents a local port from sending pause frames to remote ports. To
obtain predictable results, use send off only when remote ports are set
to receive off or receive desired.
send desired Obtains predictable results whether a remote port is set to receive on,
receive off, or receive desired.
receive on Enables a local port to process pause frames that a remote port sends.
To obtain predictable results, use receive on only when remote ports
are set to send on or send desired.
receive off Prevents remote ports from sending pause frames to a local port. To
obtain predictable results, use send off only when remote ports are set
to receive off or receive desired.
receive desired Obtains predictable results whether a remote port is set to send on,
send off, or send desired.
Table 2-5 Send Capability by Switch Type, Module, and Port
Interface Type Configured Speed Advertised Flow Control
10/100/1000BASE-TX Speed 1000 Configured flow control always
1000BASE-T Negotiation always enabled Configured flow control always
negotiated
1000BASE-X No speed nonegotiation Configured flow control negotiated
1000BASE-X Speed nonegotiation Configured flow control forced

Cisco Catalyst 4500 Series Specifications

General

Series	Catalyst 4500 Series
Category	Switch
Layer Support	Layer 2, Layer 3
Form Factor	Modular chassis
Stackable	No
Chassis Slots	3, 6, 7, 10
Power Supply Options	AC, DC
Redundancy	Power supply, Supervisor engine
Network Management	Cisco IOS Software CLI, SNMP, Cisco Prime Infrastructure
Features	Security, QoS
Port Density	Up to 384 ports per chassis
Security Features	802.1X, ACLs, DHCP Snooping, Dynamic ARP Inspection, IP Source Guard
Supervisor Engine	8-E