An engineer is configuring a Cisco IPS to protect the network and wants to test a policy before deploying it. A copy of each incoming packet needs to be monitored while traffic flow remains…

Routed mode places the IPS inline and makes it an active participant in traffic forwarding, capable of blocking, which would affect traffic flow during testing.

Passive mode involves connecting the IPS to a SPAN or tap port out-of-band, not physically inline, and while it monitors traffic copies, 'inline tap' is a more specific description for an inline, non-blocking test setup.

Transparent mode also places the IPS inline as a Layer 2 bridge and actively inspects and potentially blocks traffic, thus affecting traffic flow, which is not desired for pre-deployment testing without impact.

Inline tap mode allows the IPS device to be physically placed inline in the network path, but it operates in a listen-only fashion. It receives a copy of all traffic for analysis and policy testing without actively forwarding or dropping packets, ensuring that traffic flow remains constant.