I have frame a relay circuit. Where should I bind the ACL's? Is it on subinterface or Physical interface?
Where to bind the ACL depends somewhat on how you have configured the router. But the simple answer is that you should bind the ACL where you have assigned the IP address and where IP processing is taking place. So if you have configured the IP address on the physical interface (making it a multipoint connection) you bind the ACL on the physical interface. And if the physical interface has no IP address and the IP address in on the subinterface then you bind the ACL on the subinterface.