To implement a Layer 3 out (L3Out) inside the Cisco ACI fabric that meets the specified requirements,

the following steps should be taken:

Configure the OSPF Protocol policy with an area of 0: This step involves setting up OSPF, a link-state

routing protocol that supports hierarchical network design, as the routing protocol for the L3Out1.

Create Routed Outside object and Node Profile, selecting OSPF: This step involves creating a Routed

Outside object and associating it with a Node Profile that specifies OSPF as the routing protocol1.

Build the Interface profile, selecting Routed Sub-interface and the appropriate VLAN: This step

involves creating an Interface profile for the connection to the data center core switch, using 802.1Q

tagging for VLAN separation2.

Configure the External Network object with a network of 0.0.0.0/0: This step involves setting up the

External Network object to advertise routes to the rest of the network1.