Auto-negotiation on ethernet interfaces – Dell PowerEdge FX2/FX2s User Manual
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For example, the VLAN contains tagged members with a link MTU of 1522 and an IP MTU of 1500 and
untagged members with a link MTU of 1518 and an IP MTU of 1500. The VLAN’s Link MTU cannot be
higher than 1518 bytes and its IP MTU cannot be higher than 1500 bytes.
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 10GbE Ethernet interface 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.
NOTE: As a best practice, Dell Networking 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.
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 Dell Networking OS, 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.
Step
Task
Command Syntax
Command Mode
1.
Determine the local interface status. 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 displays link status, but not administrative status. For
link and administrative status, use the show ip interface [interface | brief]
[configuration] command.
Interfaces
107