Refer to the exhibit. The default route is not present in the routing tables of the Cisco ACI leaf switches. All static and direct routes are currently being redistributed and advertised. Which…

Enabling a BGP peer prefix policy set to Always helps manage prefix advertisement, but it does not inherently generate or leak a default route that is not already present or explicitly configured to be leaked.

Configuring a static default route with a next-hop of null on ACI node profiles is typically used for blackholing traffic, not for advertising a default route to external peers.

In Cisco ACI, the advertisement of a default route (0.0.0.0/0) out of an L3Out requires an explicit 'Default Route Leak Policy'. This policy is configured on the L3Out to instruct the ACI fabric to generate and advertise a default route to its external BGP peers, even if the default route is not internally present in the leaf routing tables as a directly learned route.

Implementing an export route map matching 0.0.0.0/0 would be effective if a default route was already present and being considered for export, but in ACI, the default route often needs to be explicitly 'leaked' into the L3Out for advertisement.