[c-nsp] TX low alarm warning

[Lukas Tribus]

> For some reason especially on 4500X 3.7 code we have also seen
> this message on ports which are left no shut, and they have an
> SFP in it. It was seriously polluting our logs so we wrote this:

That's because they introduced DOM support for some transceivers:

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/release/note/ol-37xe-4500x.html#pgfId-2796909


Still no reason to pollute the logs with this crap though. Someone
up to discuss this with TAC?



cheers,
l