Exam 300-420 topic 1 question 48 discussion

i think correct answer is d https://www.cisco.com/c/en/us/td/docs/solutions/CVD/Campus/cisco-sda-design-guide.html#FabricDHCPOverviewandDesign

https://www.cisco.com/c/en/us/td/docs/cloud-systems-management/network-automation-and-management/dna-center/tech_notes/sda_dhcp/b_cisco_sda_dhcp.html

The ip Anycast is the problem with DHCP and SDA. So the ip relay information option has to be set, it is by DNAC automagically, for DHCP to work in the fabric. https://community.cisco.com/t5/networking-knowledge-base/dhcp-in-the-fabric/ta-p/3918003

Answer A is partially correct, because there is a need to have a the DHCP Discover packet relayed to the DHCP server, however the mapping of the client to the correct DHCP scope is not done with the anycast gateway, it is done within the DHCP Option82 sub options.This is needed because every edge device in the fabric has the same anycast gateway. There would be no way for the DHCP server to get the request back to the originating requestor with out the sub options from Option 82, specifically the source RLOC. 
Look under “Fabric DHCP Packet Flow” in the link below https://www.cisco.com/c/en/us/td/docs/solutions/CVD/Campus/cisco-sda-design-guide.html

https://www.cisco.com/c/en/us/td/docs/cloud-systems-management/network-automation-and-management/dna-center/tech_notes/sda_dhcp/b_cisco_sda_dhcp.html Host DHCP Onboarding Process Fabric edge 1 (FE1) should have the following configs pushed from Cisco DNA Center: ip dhcp relay information option ip dhcp snooping vlan 3000 --> Note: All new Cisco DNA Center releases send VLAN starting from 1021. Old method of VLAN 3000 is not applicable. ip dhcp snooping

Answer D

ANSWER D https://www.cisco.com/c/en/us/td/docs/cloud-systems-management/network-automation-and-management/dna-center/tech_notes/sda_dhcp/b_cisco_sda_dhcp.html

Regarding answer A, yes the feature is enabled on the edge nodes, but the rest of the sentence doesn't make sense. The option 82 is used to map the DHCP request to the Edge device where it was originated (via RLOC). https://community.cisco.com/t5/networking-knowledge-base/dhcp-in-the-fabric/ta-p/3918003#toc-hId--1229221529

There is not such a thing as "access fabric node" in SD-Access and unless there is typo, there is not such a thing as "circuit IP"; It is circuit ID! so if answer wording in the exam is as exactly as mentioned here I will go with A

The answer could be A: https://www.cisco.com/c/en/us/td/docs/cloud-systems-management/network-automation-and-management/dna-center/tech_notes/sda_dhcp/b_cisco_sda_dhcp.html Paragraf : Host DHCP Onboarding Process

Answer is D

Answer is D

I have answer as D

Answer is D, adding for a vote

I think A is the correct.

I think "A" is corret, Is true that OPTION 82 is used, however its a feature that is and should be automatically added by the FENs. Therefore the Relay-agent has to be the FEN Fabric Edge Node.