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.
NOTE: If the interface does not come up when you congure 10/100/1000G speed, congure the interface speed using the
speed command manually on both the ends and disable autonegotiation if it is enabled.
NOTE:
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
Interfaces
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