Would you please verify when it is necessary to stack the switch modules on an ISR router?
1. HWIC + HWIC (4esw, 9esw...) - stacking must be configured with the "switchport stacking-partner" command. This is described in the documentation.
2. HWIC + NM (4esw or 9esw... + NM-16ESW-PWR or NME-16ES-1G...) - ????
3. NM + NM (NM-16ESW-PWR... + NM-16ESW...) - ???
Thanks in advance,