C H A P T E R 5 Configuring Gigabit Ethernet Switching; Sending And Receiving Pause Frames; Using Flow-Control Keywords - Cisco WS-C4003 - Catalyst 4000 Chassis Switch Software Configuration Manual

Understanding How Gigabit Ethernet Works

Sending and Receiving Pause Frames

All Catalyst Gigabit Ethernet ports can receive and process pause frames from other devices. However,
not all Catalyst Gigabit Ethernet ports can transmit pause frames to other devices.
Table 5-1
frames to other devices.
Table 5-1
Switch Type
Catalyst 4000
Catalyst 4000
Catalyst 4000
Catalyst 4000
Catalyst 4000
Catalyst 2948G
Catalyst 2980

Using Flow-Control Keywords

Table 5-2
the set port flowcontrol command.
Table 5-2
Configuration
send on
send off
send desired
receive on
receive off
receive
desired
Software Configuration Guide—Catalyst 4000 Family, Catalyst 2948G, Catalyst 2980G, Releases 6.3 and 6.4
5-2
identifies the Catalyst Gigabit Ethernet switches, modules, and ports that can transmit pause
Send Capability by Switch Type, Module, and Ports
Module
All modules except WS-X4418-GB,
WS-X4412-2GB-T, and
WS-X4416-2GB-TX
WS-X4418-GB
WS-X4418-GB
WS-X4412-2GB-T
WS-X4412-2GB-T
All ports
All modules
describes guidelines for using different configurations of the send and receive keywords with
Send and Receive Keyword Configurations
Description
Enables a local port to send pause frames to a remote port. Use send on when a
remote port is set to receive on or receive desired.
Prevents a local port from sending pause frames to a remote port. Use send off when
a remote port is set to receive off or receive desired.
Indicates preference to send pause frames, but autonegotiates flow control. You can
use send desired when a remote port is set to receive on, receive off, or receive
desired.
Enables a local port to process pause frames that a remote port sends. Use receive
on when a remote port is set to send on or send desired.
Prevents a local port from processing pause frames. Use receive off when a remote
port is set to send off or send desired.
Indicates preference to process pause frames, but autonegotiates flow control. You
can use receive desired when a remote port is set to send on, send off, or send
desired.
Chapter 5 Configuring Gigabit Ethernet Switching
Ports
All ports except for the
oversubscribed ports listed below
Uplink ports (1–2)
Oversubscribed ports (3–18)
Uplink ports (13–14)
Oversubscribed ports (1–12)
All ports
All ports
Send
No
No
Yes
No
Yes
No
No
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