Cisco Catalyst 3550 User Manual

2-117
Catalyst 3550 Multilayer Switch Command Reference
OL-8566-02
Chapter 2 Catalyst 3550 Switch Cisco IOS Commands
flowcontrol
flowcontrol
Use the flowcontrol interface configuration command to set the receive or send flow-control value for
an interface. When flow control send is on for a device and it detects any congestion at its end, it notifies
the link partner or the remote device of the congestion by sending a pause frame. When flow control
receive is on for the remote device and it receives a pause frame, it stops sending any data packets. This
prevents any loss of data packets during the congestion period.
Use the receive off and send off keywords to disable flow control.
flowcontrol {receive | send} {desired | off | on}
Note On the Catalyst 3550 switch, Gigabit Ethernet ports can receive and send pause frames; Fast Ethernet
ports can receive only pause frames. Therefore, for 10/100 ports, the send keyword is not available.
Syntax Description
Defaults The defaults for Gigabit Ethernet interfaces are flowcontrol receive off and flowcontrol send desired.
The defaults for Fast Ethernet interfaces are flowcontrol receive off and flowcontrol send off.
Command Modes Interface configuration
Command History
receive Set whether the interface can receive flow-control packets from a remote device.
send Set whether the interface can send flow-control packets to a remote device. This
keyword is not available for 10/100 Mbps interfaces.
desired When used with receive, allows an interface to operate with an attached device that is
required to send flow-control packets or with an attached device that is not required to
but can send flow-control packets.
When used with send, the interface sends flow-control packets to a remote device if the
remote device supports it.
off When used with receive, turns off an attached device’s ability to send flow-control
packets to an interface. When used with send, turns off the local port’s ability to send
flow-control packets to a remote device.
on When used with receive, allows an interface to operate with an attached device that is
required to send flow-control packets or with an attached device that is not required to
but can send flow-control packets.
When used with send, the interface sends flow-control packets to a remote device if the
remote device supports it.
Release Modification
12.1(4)EA1 This command was introduced.

Cisco Catalyst 3550 Specifications

General

Category	Switch
QoS	Yes
Form Factor	Rack-mountable
Manageable	Yes
RAM	64 MB
Model	Catalyst 3550
Uplink Ports	2 x GBIC (Gigabit Interface Converter) or SFP (Small Form-factor Pluggable)
Layer Support	Layer 3
VLAN Support	Yes
MAC Address Table Size	12000 entries
Routing Protocol	EIGRP
Features	QoS
Operating Temperature	32 to 113°F (0 to 45°C)
Operating Humidity	10 - 95% (non-condensing)
Ports	24 or 48 10/100 ports