Exam 300-620 topic 1 question 47 discussion

It is A. The source MAC address is learnt as local endpoint. https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-739989.pdf Refer to Table 6 which says, Local endpoint learning with an incoming packet from L3Out to Cisco ACI: Only the source MAC address is learned as a local endpoint. The source IP address is not learned as a local endpoint.

Isn't it A? As per below document, in endpoint learning behavior for traffic coming in from L3 out, only source mac address will be learned as local endpoint and of course that will be on ingress leaf for traffic coming in https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-739989.html

C is correct.. When traffic is received on an ACI leaf switch from a Layer 3 Out (L3Out) connection, the source IP address of the traffic is learned as a remote endpoint. This is because the endpoint is external to the ACI fabric and communicates with the fabric through the L3Out. The ACI fabric tracks such endpoints as remote entities since they are not directly connected to the fabric as local endpoints. • Local Endpoint Learning: Refers to endpoints connected directly to the ACI leaf switch on an access port or through a Layer 2 domain. • Remote Endpoint Learning: Refers to endpoints external to the ACI fabric, typically reachable via an L3Out or through VXLAN tunnels from another leaf.

I think B is correct. A is a description of "dest MAC", I thought.

It is A https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-739989.html#L3Outendpointlearningconsiderations

Scenario 1 Local endpoint learning with an incoming packet from L3Out to Cisco ACI: Only the source MAC address is learned as a local endpoint. The source IP address is not learned as a local endpoint.

A Scenario 1 Local endpoint learning with an incoming packet from L3Out to Cisco ACI: Only the source MAC address is learned as a local endpoint. The source IP address is not learned as a local endpoint. Scenario 2 Remote endpoint learning with an incoming packet from L3Out to Cisco ACI: No source MAC or IP address is learned as a new remote endpoint by a packet.* https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-739989.html

https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-739989.html Local endpoint learning with an incoming packet from L3Out to Cisco ACI: Only the source MAC address is learned as a local endpoint. The source IP address is not learned as a local endpoint.

This question is not stating where the L3Out is connected and therefore it is not possible to determine it is a local of remote endpoint.

Is it not B ? The source MAC on this leaf is learnt as a remote endpoint given the L3 out from which the end host is being may be on another leaf . It does not say it's the same leaf as what the L3 configured on ?

Local endpoint learning with an incoming packet from L3Out to Cisco ACI: Only the source MAC address is learned as a local endpoint. The source IP address is not learned as a local endpoint.