[j-nsp] EX4500 SFP+ laser lit when interface is admin down and vice versa

[Tore Anderson]

* Jed Laundry

> I haven't seen this particular issue, and I'm not sure about the
> EX4500, but on a EX4550 you can:
> 
> > start shell user root
> 
> % lcdd 0 chassism
> 
> chassism<0>#xcvr enable ge-0/0/30
> devNum:0, portNum:49
> 
> HERE BE DRAGONS: any errors/warnings in chassism (i.e., finger
> fudges) will cause the device to kernel panic and reboot... Been
> there, done that...

So, for the archive, I tried this in a maintenance window. No panics or
reboots, but it turned out that chassism was confused in the same way
the rest of the switch was, in other words: "xcvr enable" actually
switched off the Tx laser, while "xcvr disable" switched it on. So I
suppose that doing "xcvr disable" would have solved my issue in the
short term and would have saved me a trip to the colo to move the link
to an unaffected port.

Only after rebooting the switch (as part of an NSSU to 12.3R9) did the
port start to work normally again.

Thanks for the tip, Jed!

Tore