Not a bright question but I will still ask it:
We inform the customer that SUP / Power Supply / Line cards in CAT 6500 are or hot swappable. Customer asks which is SAFER - Hot swap or power down and swap.
I say hot swap is safer as long as we are changing like card for like card and like OS for like OS. Customer said he heard otherwise from more reliable source. Not sure what he means by more reliale source - may be from Cisco itself.