Which are valid uRPF operation modes? (Choose two.)

Unicast Reverse Path Forwarding (uRPF) is a security feature that helps prevent IP spoofing by verifying the source IP address of incoming packets. The two valid operation modes are Strict mode and Loose mode. In Strict mode, the router checks if the source IP address exists in its routing table and if the incoming interface is the best path back to that source. If either condition fails, the packet is dropped. This mode offers the highest level of security but can drop legitimate traffic if asymmetric routing is present. In Loose mode, the router only checks if the source IP address exists in its routing table via any interface. It does not verify the incoming interface. This mode is more flexible and suitable for environments with asymmetric routing but offers less stringent anti-spoofing protection than Strict mode. "Open mode," "Closed mode," and "Block mode" are not standard uRPF operation modes.