Exam ANS-C00 topic 1 question 56 discussion

A and E are the correct answers. B is incorrect. https://docs.aws.amazon.com/directconnect/latest/UserGuide/getting_started.html#createvirtualinterface. "BGP information: A public or private Border Gateway Protocol (BGP) Autonomous System Number (ASN) for your side of the BGP session. If you are using a public ASN, you must own it. If you are using a private ASN, it must be in the 64512 to 65535 range. Autonomous System (AS) prepending does not work if you use a private ASN for a public virtual interface. An MD5 BGP authentication key. You can provide your own, or you can let Amazon generate one for you. (Public virtual interface only) Prefixes you want to advertise: Public IPv4 routes or IPv6 routes to advertise over BGP. You must advertise at least one prefix using BGP, up to a maximum of 1,000 prefixes."

A. Use Local Pref to control outbound traffic. E. Advertise more specific prefixes over one Direct Connect connection.

Correct answers A & E

AWS has a software limitation - they can't prepending ASN for private ASN for a public interface. so A, E

A & E, The local preference is local to the AS, and it is for outbound routing.

A and B... if you prepend the routes you advertise via one Direct Connect, it will make the inbound traffic flows via the link with no preppend...so B is right if you set local preference in one neighbor higher, the outbound will go trough it, A is right E could work, but is a bad solution

https://aws.amazon.com/premiumsupport/knowledge-center/dx-create-dx-connection-from-public-vif/ Longer Prefixe is definitely an option for private ASN. But, Local Preference is listed as an option for Public ASN ...

A & E; Afer reading clark.

AE https://aws.amazon.com/premiumsupport/knowledge-center/dx-create-dx-connection-from-public-vif/

Does someone already try to use "Private-VIFs" + Private ASN + AS-Prepending? Is that works? I have not found anything related to "Private-Vifs" when using with AS-Prepending

Inbound and outbound in reference to AWS or to on-premises network ?

A&E https://aws.amazon.com/premiumsupport/knowledge-center/dx-create-dx-connection-from-public-vif/ If you're using a private ASN: AS prepending doesn't work if you use a private ASN for a public virtual interface

A,B as below: https://forums.aws.amazon.com/thread.jspa?threadID=264393

A,B ref:https://aws.amazon.com/premiumsupport/knowledge-center/dx-create-dx-connection-from-public-vif/

And B , Communities are used with direct connect to control inbound traffic..

A, E is correct.

Answer is AE. https://forums.aws.amazon.com/message.jspa?messageID=813305 "Public VIF : AS path prepend WILL NOT be honored if you are using a private ASN"