got this on the exam, 'D' is correct (you can ignore the typo here, it is correctly spelled on the exam) D - is enabling the feature A - is using it for best-path calculation see: https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/217020-bgp-rpki-with-xr7-cisco8000-whitepaper.html

According to the link posted, it says: To enable the router for as-origin validity check, activate this command for the concerned address family. router bgp 100 address-family ipv4 unicast bgp origin-as validation enable ! Then it says: When you ""activate this command"", it causes the router to scan the prefixes present in its BGP table against the ROA information received from the validator and one of the three states is assigned to prefixes . RP/0/RP0/CPU0:Cisco8000#show bgp origin-as validity !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! In the exhibit you see the following CLI Command: show bgp origin-as validity This would mean the feature is already enabled, otherwise you won't be able to check/execute show bgp origin-as validity So, I would go for D.

https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/217020-bgp-rpki-with-xr7-cisco8000-whitepaper.html By default, the router gets ROAs from the validator but does not start using them until it is configured to do so. As a result, these prefixes are marked as ‘D’ or disabled... To enable the router for as-origin validity checking, activate this command for the specific address family. router bgp <#AS> address-family ipv4 unicast bgp origin-as validation enable it makes the router scan the prefixes in its BGP table against the ROA information received from the validator and one of the three states is assigned to prefixes. To enable the router to use prefix validation state information while making the best path calculation, this command is needed. router bgp <#AS> address-family ipv4 unicast bgp bestpath origin-as use validity I would go for D, since it just needs to scan the prefix

i go for A. mismatch in the router name in the prompt

Selected Answer: D this is the first command needed to use the requested feature

Selected Answer: D This is not part of the Cisco SPCORE e-learning syllabus. Based on the explanation, I will choose D

Selected Answer: D Step-3: To let the router use prefix validation state information when doing the best path calculation, this command is required. It is not enabled by default, since it lets you choose not to use the validity information for best path calculation while still allowing you to use it in route policies, which are discussed later in this document. router bgp 100 address-family ipv4 unicast bgp bestpath origin-as use validity ! RP/0/RP0/CPU0:Cisco8000#show bgp 203.0.113.0/24 Thu Jan 21 05:30:13.858 UTC BGP routing table entry for 203.0.113.0/24 Versions: Process bRIB/RIB SendTblVer Speaker 31 31 Last Modified: Jan 21 00:03:33.344 for 05:26:40 https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/217020-bgp-rpki-with-xr7-cisco8000-whitepaper.html

Selected Answer: D Step-2: To enable the router for as-origin validity checking, turn on this command for the relevant address family. router bgp 100 address-family ipv4 unicast bgp origin-as validation enable When you turn on this command, it makes the router compare the prefixes in its BGP table with the ROA information received from the validator, and one of the three states is assigned to prefixes . RP/0/RP0/CPU0:Cisco8000#show bgp origin-as validity Origin-AS validation codes: V valid, I invalid, N not-found, D disabled Network Next Hop Metric LocPrf Weight Path V*> 203.0.113.0/24 10.0.12.2 0 0 8100 ? I* 203.0.113.1/24 10.0.12.2 0 0 8100 ? N*> 192.168.122.1/32 10.0.12.2 0 0 8100 ?

Selected Answer: D Step-1: By default, the router pulls ROAs (Route Origin Authorization) from the validator but does not start using them until it is set up to do so. Because of that, these prefixes are marked as ‘D’ or disabled. RP/0/RP0/CPU0:Cisco8000#show bgp origin-as validity Status codes: s suppressed, d damped, h history, * valid, > best i - internal, r RIB-failure, S stale, N Nexthop-discard Origin codes: i - IGP, e - EGP, ? - incomplete Origin-AS validation codes: V valid, I invalid, N not-found, D disabled Network Next Hop Metric LocPrf Weight Path D*> 203.0.113.0/24 10.0.12.2 0 0 8100 ? D*> 203.0.113.1/24 10.0.12.2 0 0 8100 ? D*> 192.168.122.1/32 10.0.12.2 0 0 8100 ?