[c-nsp] full duplex mismatch speed - dynamips

[John Neiberger]

On Thu, Aug 19, 2010 at 10:07 AM, Adam Armstrong <lists at memetic.org> wrote:
> On 17/08/2010 23:50, Justin M. Streiner wrote:
>>
>> On Tue, 17 Aug 2010, Alessandro Braga wrote:
>>
>>> Verify duplex and speed configurations on interface, the rule is:
>>> autoXauto, forcedXforced. If problem not solve, disable cdp.
>>
>> Also, while auto speed/duplex negotiation is fine for user
>> workstation/PC ports in most cases, I recommend against using it on your
>> network infrastructure if you can help it.
>
> This is horribly terrible advice.
>
> Autonegotiation should always be used as default, nailing should be the fix
> for when things don't work, and where very old devices don't do autoneg
> properly.
>
> Note that for gigabit, autonegotiation is MANDATORY.
>
> adam.

Adam, you are my new best friend. I've been saying this for the past
few years and people still think I'm crazy. I flat out refuse to
manually configure speed and duplex for someone unless it is
demonstrated (or I can verify) that a duplex mismatch is actually
happening or there is some other extenuating circumstance that
requires it.