We currently have many etherchannels in our network, most of which are legacy. These are configured in a 'mode ON' state.
We are now looking to configure all port channels in a 'mode desirable non-silent' state.
We have been advised this is the recommended mode.
I wanted to know what is the benefit of using such mode and whether it gives us any real benefit.
What are the risks for us to carry on using the Mode ON state ??
Thanks in advance for your help.
AFAIK, in normal operation there is no risk in using the ON mode. It may even be safer that the dynamic mode.
What is the downside? If you are re-cabling and you connect a switch via a port that is in access mode, the connection will not revert to access mode. But that is not really an operation risk because it could be considered as part of the re-cabling exercise.
The benefit of using "desirable" is that you do not ever have to configure the port - it will automatically negotiate trunking mode if it can. Or not, as the case may be. But that is not really an operational risk.
Personnally, I prefer the "ON" mode, and use it on all my inter-switch links. That way I know exactly where I stand w.r.t. trunking on each link. But it does mean I have to re-configure when I replace an access connection with a trunk or vica versa.