Hi,
Something i came across to and thought could be worth while reporting it since i havent seen any reference to it elsewhere:
We've configured a few "source remote port mirror rules" for a few VMs, in a way that each VM had 3 vNics that were mirrored.
long story shot: one VM had one vNic that was E1000 and not VMXNET3 like all the others, each time i enabled the "source remote port mirror" rule for the E1000 vNic, all other port mirrors (from this VM and other VMs located on the same ESX) stopped working. problem was solved after i removed the vNic and created a new one, this time a VMXNET3 vNic.
didnt see any reference about E1000/VMXNET3 regarding vSphere Port Mirroring. New bug maybe?