[j-nsp] GE/10GE link-mode config on M/T-series has no effect

[Chuck Anderson]

On Tue, Dec 11, 2007 at 03:17:17PM +0200, Pekka Savola wrote:
> Just as a heads-up, apparently GE/10GE 'link-mode full-duplex' 
> configuration on M/T-series routers has no effect, the interface stays 
> with auto-negotiate.
> 
> Some versions of current software report warnings on commits to syslog 
> but these warnings are being removed.  The configuration syntax is 
> still be supported but it's a no-op.
> 
> I wonder if there is a valid deployment scenario where you will want 
> to force full-duplex instead of doing auto-negotiation.  Now would 
> probably be a good time to start talking to your local Juniper reps 
> :-)

It is a requirement of the GigE standard to do autonegotiation.  
Turning it off would be a violation of the standard.  Besides, when 
was the last time you saw a GigE PHY that supported Half-Duplex?  
Autonegotiation on GigE is more about flow-control settings than 
duplex settings.  I assume the situation with 10GE is similar.