Command Line Interface

4-160

4
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 (4-157)
capabilities (flowcontrol, symmetric) (4-158)

media-type

This command forces the port type selected for combination ports 21-24. 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 module not installed).
sfp-preferred-auto - Uses SFP port if both combination types are
functioning and the SFP port has a valid link.
Default Setting
sfp-preferred-auto
Command Mode
Interface Configuration (Ethernet - Ports
21-24/45-48
)
Example
This forces the switch to use the built-in RJ-45 port for the combination port 21.

shutdown

This command disables an interface. To restart a disabled interface, use the no
form.
Syntax
[no] shutdown
Console(config)#interface ethernet 1/5
Console(config-if)#flowcontrol
Console(config-if)#no negotiation
Console(config-if)#
Console(config)#interface ethernet 1/21
Console(config-if)#media-type copper-forced
Console(config-if)#