TX low alarm warning

For some reason especially on3.7 code we have also seen this message on ports which are left no shut, and they have an SFP in it.

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