[j-nsp] EX4200 VCP port statistics not showing errors when it should

[Chuck Anderson]

On Wed, Mar 18, 2015 at 01:44:10PM -0400, Chuck Anderson wrote:
> Has anyone experienced a problem where an EX4200 VC was dropping
> packets (30-50% packet loss or higher) across a certain VCP cable, but
> the "show virtual-chassis vc-port statistics extensive" command showed
> no errors, and the "request virtual-chassis device-reachability"
> command didn't show any problems either?

I forgot to follow up on this.  It was CoS enabled on the vcp-* ports.
Turning it off "fixed" the issue.  I think the real fix went into
12.3R9-S10 or 12.3R11, but I'm chicken to reenable CoS on the vcp-*
ports.