Which of the following is NOT an option for internal network definition of Anti-spoofing?

Specific is a valid Anti-spoofing topology option that defines the protected network behind an interface using a manually selected network or group object.

Route-based topology - derived from the gateway routing table - is used in Check Point for defining VPN domains, not for configuring Anti-spoofing internal network topology. The valid Anti-spoofing topology options are: Not Defined, Network defined by the interface IP and Net Mask, and Specific (derived from a selected network object), making Route-based the option that does NOT belong in this context.

Network defined by the interface IP and Net Mask is a valid Anti-spoofing option that automatically derives the protected network from the interface's IP address and subnet mask configuration.

Not Defined is a valid Anti-spoofing setting that effectively disables topology enforcement on the selected interface.