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

[Tore Anderson]

Hi,

I've got an EX4500 running 12.3R8.7 that has a port that's misbehaving
in a rather odd way: If I disable the interface in the config and
commit, the laser is turned on (normal Tx levels in show interfaces
diagnostics optics). If I re-enable the interface and commit, the laser
is switched off (Tx level of -Inf dBm). So it's doing precisely the
opposite of what I'd expect it to.

When I commit the configuration that enables the interface, the
following message is logged:

chassism[1405]: Tx Disable called for port: 0, enable: 0

I've tried multiple SFP+ modules and they all behave the same. Also
I've tried re-seating the SFP+ with as many different combinations of
the interface being disabled/enabled when I remove/insert the module as
I could think of, no luck. Finally it's only impacting port 0, e.g.,
port 4 works as expected (i.e., Tx off when interface is disabled and
on when enabled) - even with the very same module that don't work right
when inserted in port 0.

Anyone seen anything like that? I'm hoping to find a way fix it without
needing a maintenance window to reboot it.

Tore