Command Line Interface
4-172
4
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
• 1000BASE-T does not support forced mode. Auto-negotiation should always
be used to establish a connection over any 1000BASE-T port or trunk.
• Flow control can eliminate frame loss by “blocking” traffic from end stations or
segments connected directly to the switch when its buffers fill. When enabled,
back pressure is used for half-duplex operation and IEEE 802.3-2005
(formally IEEE 802.3x) for full-duplex operation.
• 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 (4-170)
capabilities (flowcontrol, symmetric) (4-170)
media-type
This command forces the port type selected for combination ports 45-48
(DG-GS1550). 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.
Console(config)#interface ethernet 1/5
Console(config-if)#flowcontrol
Console(config-if)#no negotiation
Console(config-if)#
Summary of Contents for DG-GS1550
Page 24: ...Tables xxx ...
Page 46: ...Initial Configuration 2 10 2 ...
Page 642: ...Command Line Interface 4 342 4 ...
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