I have a CCNA lab with 3 1921 running same software; "usbflash0:c1900-universalk9-mz.SPA.157-3.M2.bin" C1900 Software (C1900-UNIVERSALK9-M), Version 15.7(3)M2, RELEASE SOFTWARE (fc2) System Bootstrap, Version 15.0(1r)M16, RELEASE SOFTWARE (fc1). I am...