I have a configuration of 2 switches with a router which is not pinging pc in a different vlan. I have created 3 different vlans on each switch, configured access ports to pc, configured trunk between the 2 switches and another trunk between switch and router. I also configured sub interfaces on the router but still I'm getting an error destination unreachable when I ping to a different vlan. Pcs in same vlan are pinging successfully.