Administrator Guide

Auto-Negotiation on Ethernet Interfaces
By default, auto-negotiation of speed and full duplex mode is enabled on 10/100/1000 Base-T Ethernet interfaces. Only 10GE interfaces do
not support auto-negotiation.
When using 10GE interfaces, verify that the settings on the connecting devices are set to no auto-negotiation.
The local interface and the directly connected remote interface must have the same setting, and auto-negotiation is the easiest way to
accomplish that, as long as the remote interface is capable of auto-negotiation.
NOTE: As a best practice, Dell Networking recommends keeping auto-negotiation enabled. Only disable auto-negotiation on
switch ports that attach to devices not capable of supporting negotiation or where connectivity issues arise from interoperability
issues.
Setting the Speed of Ethernet Interfaces
To discover whether the remote and local interface requires manual speed synchronization, and to manually synchronize them if necessary,
use the following command sequence.
1 Determine the local interface status. Refer to the following example.
EXEC Privilege mode
show interfaces [interface | stack—unit stack-unit-number] status
2 Determine the remote interface status.
EXEC mode or EXEC Privilege mode
[Use the command on the remote system that is equivalent to the rst command.]
3 Access CONFIGURATION mode.
EXEC Privilege mode
config
4 Access the port.
CONFIGURATION mode
interface interface-type
5 Set the local port speed.
INTERFACE mode
speed {10 | 100 | 1000 | 10000 | auto}
NOTE
: If you use an active optical cable (AOC), you can convert the QSFP+ port to a 10 Gigabit SFP+ port or 1 Gigabit
SFP port. You can use the speed command to enable the required speed.
6 Optionally, set full- or half-duplex.
INTERFACE mode
duplex {half | full}
7 Disable auto-negotiation on the port.
INTERFACE mode
no negotiation auto
If the speed was set to 1000, do not disable auto-negotiation.
8 Verify conguration changes.
422
Interfaces