Dell 9.7(0.0) Plumbing Product User Manual


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The VLAN link MTU and IP MTU must be less than or equal to the link MTU and IP MTU values
configured on the VLAN members.
For example, the VLAN contains tagged members with Link MTU of 1522 and IP MTU of 1500 and
untagged members with Link MTU of 1518 and 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
By default, auto-negotiation of speed and 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.
For 10/100/1000 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.
Set Auto-Negotiation Options
The negotiation auto command provides a mode option for configuring an individual port to forced
master/ forced slave once auto-negotiation is enabled.
CAUTION: Ensure that only one end of the node is configured as forced-master and the other is
configured as forced-slave. If both are configured the same (that is, both as forced-master or
both as forced-slave), the show interface command flaps between an auto-neg-error and
forced-master/slave states.
Example of the negotiation auto Command
Dell(conf)# int tengig 0/0
Dell(conf-if-te-0/1)#neg auto
Dell(conf-if-te-0/1)# ?
end Exit from configuration mode
exit Exit from autoneg configuration mode
mode Specify autoneg mode
no Negate a command or set its defaults
show Show autoneg configuration information
Dell(conf-if-te-0/1)#
mode ?
forced-master Force port to master mode
forced-slave Force port to slave mode
Dell(conf-if-te-0/1)#
For details about the speed, duplex, and negotiation auto commands, refer to the Interfaces
chapter of the Dell Networking OS Command Reference Guide.
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Interfaces