Reference Guide

140 | 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 1GbE and 10GbE Ethernet interfaces
on an Aggregator.
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 10-20 on page 141).
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 10-19.
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 10-19) displays link status, but not administrative
status. For link and administrative status, use the show ip interface [interface | brief] [configuration] command.