250 | Interfaces
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Auto-Negotiation on Ethernet Interfaces 
Setting Speed and Duplex Mode of Ethernet Interfaces
By default, auto-negotiation of speed and duplex mode is enabled on 100/1000/10000 Base-T Ethernet 
interfaces. Only 10GbE interfaces do not support auto-negotiation. When using 10GbE 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. 
Auto-negotiation is the easiest way to accomplish these settings, as long as the remote interface is capable 
of auto-negotiation.
For 100/1000/10000 Ethernet interfaces, the 
negotiation auto command is tied to the speed command. 
Auto-negotiation is always enabled when the 
speed command is set to 1000 or auto. In FTOS, the speed 
1000
 command is an exact equivalent of speed auto 1000 in IOS. 
To discover whether the remote and local interface require manual speed synchronization, and to manually 
synchronize them if necessary, follow these steps (also refer to Figure 13-26 on page 251). 
Note: As a best practice, Dell Force10 recommends keeping auto-negotiation enabled. Auto-negotiation 
should only be disabled on switch ports that attach to devices not capable of supporting negotiation or 
where connectivity issues arise from interoperability issues.
Step Task Command Syntax Command Mode
1 Determine the local interface status. Refer 
to Figure 13-25.
show interfaces [interface] status
EXEC Privilege
2 Determine the remote interface status. [Use the command on the remote system 
that is equivalent to the above command.]
EXEC 
EXEC Privilege
3 Access CONFIGURATION mode.
config
EXEC Privilege
4 Access the port. interface interface slot/port CONFIGURATION
5 Set the local port speed.
speed {100 | 1000 | 10000 | auto}
INTERFACE
6 Optionally, set full- or half-duplex.
duplex {half | full}
INTERFACE
7 Disable auto-negotiation on the port. If the 
speed is set to 1000, you do not need to 
disable auto-negotiation
no negotiation auto
INTERFACE
8 Verify configuration changes.
show config
INTERFACE
Note: The show interfaces status command (Figure 13-25) displays link status, but not administrative 
status. For link and administrative status, use the show ip interface [interface | brief] [configuration] command.