Ethernet - speed and duplex settings on an ISR4431
When setting up the speed and duplex settings on a Cisco ISR4431, the configuration parameters must be set in a particular order.
First of all, the interface itself must be up. If it is not, the speed and duplex options are not made available to you. If you try to configure them, you will get an error message similar to the following:
% Invalid input detected at '^' marker
Secondly, once the interface is up, you must first follow these steps in this order:
- Ensure that the interface has been set to
negotiation auto
- Then set the interface to
no negotiation auto
to disable the auto-negotiation. - Finally, set the speed and duplex settings that you desire.
Other devices may have similar processes that must be followed, however, this has been confirmed for the ISR4431.
Links:
https://forum.networklessons.com/t/interface-speed-and-bandwith/15285/7?u=lagapidis
https://community.cisco.com/t5/routing/duplex-and-speed-commands-missing-isr-4331/td-p/3392703
https://www.cisco.com/c/en/us/support/routers/4441-x-integrated-services-router-isr/model.html