ISR 4331 - Auto-negotiate set. Issue no neg auto and router crashes

[DKershner12]

 So interface gig 0/0/0 interfaces with the LEC. Currently it has changed to half duplex.

 I try "duplex full" and the errors says I can't make the change because auto-negotiation is active.

 I then issue "no neg auto" and the router loses connectivity.

 Now the LEC verified what config they have 100/full with no neg auto.

 So I'm figuring I can't make the change as the config doesn't match between the LEC port and mine.
 My conclusion is I have to go onsite, console in. Do "no neg auto" add speed 100 and duplex full.

 Then it should come back up....assuming the LEC has it correct.    Correct?

[Leo Laohoo]

What is the handover from the carrier?  Is it copper or fibre?

[DKershner12]

Copper handoff

[Leo Laohoo]

If this is a copper handoff, then the port cannot be set to "full duplex" or else there will be a duplex mismatch and the ports will operate at half the speed (due to half duplex).

[paul driver]

Hello

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@DKershner12 wrote:

 Now the LEC verified what config they have 100/full with no neg auto.
 My conclusion is I have to go onsite, console in. Do "no neg auto" add speed 100 and duplex full.

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Is the reason you cannot do this remotely because its the interface you use to gain access to the switch? 

[DKershner12]

That's correct.