[j-nsp] QFX3500 optics lock?

[sthaug at nethelp.no]

> However - crappy though they were, imagine my irritation when, even with 
> "service unsupported-transceiver", a duplicate SFP serial number caused 
> err-disable on BOTH ports, and requires BOTH transceivers to be removed.
> 
> It's not obvious to me that this is a reasonable response; the 1st 
> transceiver was in, and forwarding packets. Why disable it? What 
> possible "value" does that add?
> 
> So even the Cisco model is a bit more restrictive than first 
> appearances. It's only "some" unsupported transceivers.

I believe I've also seen the problem that switches which *can* read
DOM values (e.g. 3560, ME3400) won't do this for non-cisco branded
SFPs (e.g. when you need to use "service unsupported-transceiver")
even when the SFPs themselves support this (and will happily supply
optical signal levels when inserted for instance into a Juniper MX
router).

Steinar Haug, Nethelp consulting, sthaug at nethelp.no