Your network operations team is deploying Access Control Lists (ACLs) across your Internet gateways. They wish to place an ACL inbound on the Internet gateway interface facing the core network (the…

The inside local address is the private IP address assigned to an internal host as seen from inside the network; because an inbound ACL on the inside interface is processed before NAT translation takes place, the source address in the packet header still holds the original private address, which is the inside local address in Cisco NAT terminology.

The outside local address is the IP address of an external host as seen from the inside network, which is the destination address of outbound traffic - not the source address of traffic originating from inside hosts.

The inside global address is the translated public IP representing an inside host as seen from the outside; this address only exists after NAT translation has been applied, which has not yet occurred when an inbound ACL on the inside interface is evaluated.

The outside global address is the IP address of an external host as seen from outside the network and has no relevance as the source address of traffic originating from internal hosts traversing the inside interface.