Exam 300-620 topic 1 question 218 discussion

here are two methods to advertise a default route (0.0.0.0/0) from BGP L3Out to the outside. 1. Transit Routing 2. Default Route Leak Policy Transit Routing will advertise a default route that is learned from another L3Out or possibly a static route configured on another L3Out. https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/guide-c07-743150.html

A default route can also be advertised out using a Default Route Leak policy. This policy supports advertising a default route if it is present in the routing table or it always supports advertising a default route. The Default Route Leak policy is configured in the L3Out connection. https://www.cisco.com/c/en/us/td/docs/switches/datacenter/aci/apic/sw/2-x/L3_config/b_Cisco_APIC_Layer_3_Configuration_Guide/b_Cisco_APIC_Layer_3_Configuration_Guide_chapter_010100.html Criteria Use “Leak Default Route in Addition” when a default route needs to be advertised on top of other routes. Use “Leak Default Route Only” when only a default route should be advertised. When “Leak Default Route Only” is selected, deny-all is applied to outbound route-maps on each BGP peer in this L3Out. https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/guide-c07-743150.html

For external connections to the fabric that only require a default route, there is support for originating a default route for OSPF, EIGRP, and BGP L3Out connections. If a default route is received from an external peer, this route can be redistributed out to another peer following the transit export route control as described earlier in this article. A default route can also be advertised out using a Default Route Leak policy. This policy supports advertising a default route if it is present in the routing table or it always supports advertising a default route. The Default Route Leak policy is configured in the L3Out connection. When creating a Default Route Leak policy, follow these guidelines: For BGP, the Always property is not applicable. When configuring the Scope property, choose Outside. For OSPF, the scope value Context creates a type-5 LSA while the Scope value Outside creates type-7 LSA. For EIGRP, when choosing the Scope property, you must choose Context.

Correct, it's A.