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'no-auto-negotiation' option is set for a GigE interface, but it is still showing as autonegotiation

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Knowledge Base ID: KB28600
Last Updated: 14 Jan 2014
Version: 1.0


This article explains the reason why the no-auto-negotiation option for a copper Gigabit Ethernet interface appears to not be working.

Problem or Goal:

The 'no-auto-negotiation' option is configured for your GigE interface as follows, and it commits without a warning.

root@srx# show interfaces ge-0/0/6
gigether-options {

However, the logs report the following:

Invalid parameter, ge-0/0/6, Auto-negotiation is mandatory for 1000BASE-TX.

Why did it commit without warning, if the parameter is invalid?


In the current design, Junos OS is not able to block this specific interface configuration, i.e "no-auto-negotiation" in the CLI as there are various platforms, I/O cards and interface types. If the speed is 1G, autonegotiation will be enabled by default, regardless of your setting "no-auto-negotiation" under the interface configuration.


To avoid the message "Invalid parameter, ge-0/0/6, autonegotiation is mandatory for 1000BASE-TX", remove the no-auto-negotiation option, as autonegotiation is enabled by default and cannot be changed.


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