Gigabit Ethernet Switch Management Guide

I NTERFACE C OMMANDS
4-179
• To force flow control on or off (with the flowcontrol or no
flowcontrol command), use the no negotiation command to disable
auto-negotiation on the selected interface.
• When using the negotiation command to enable auto-negotiation,
the optimal settings will be determined by the capabilities command.
To enable flow control under auto-negotiation, “flowcontrol” must
be included in the capabilities list for any port
• Avoid using flow control on a port connected to a hub unless it is
actually required to solve a problem. Otherwise back pressure
jamming signals may degrade overall performance for the segment
attached to the hub.
Example
The following example enables flow control on port 5.
Related Commands
negotiation (4 -176)
capabilities (flowcontrol, symmetric) (4-177)
media-type
This command forces the port type selected for combination ports 21-24/
45-48. Use the no form to restore the default mode.
Syntax
media-type mode
no media-type
mode
• copper-forced - Always uses the built-in RJ-45 port.
• sfp-forced - Always uses the SFP port (even if a module is not
installed).
• sfp-preferred-auto - Uses SFP port if both combination types
are functioning and the SFP port has a valid link.
Console(config)#interface ethernet 1/5
Console(config-if)#flowcontrol
Console(config-if)#no negotiation
Console(config-if)#