Any easy way to see which "side" traffic came in on a Nexus vPC?

I know depending on the l2 algorithm the traffic would be sent down either physical link. It's then forwarded by whichever vPC Peer gets the packet first. (Because they both forward on behalf of the VIP even if it's not the HSRP Master that got the packet.)

So that leaves it kinda tough to tshoot something if you can't really predict which physical path is being taken.

Is the best way to just down one physical side of the vPC one at a time until you find the "bad link?"