AWS Certified Advanced Networking Specialty · Free Practice Question Hard
Question 3
The networking team at a company wants to set up two AWS Direct Connect connections between its on-premises data center and the AWS Cloud. The Direct Connect connections need to be set up in an Active/Active configuration from a public virtual interface using a public ASN.
As an AWS Certified Networking Specialist, which solution would you recommend for this requirement?
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A
Active/active configuration from a public virtual interface is not supported using public ASN
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B
Set up the customer gateway to advertise the longer prefix on your primary connection
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C
Configure your customer gateway to advertise the same prefix with the same Border Gateway Protocol (BGP) attributes on both public virtual interfaces
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D
Set up the customer gateway to advertise the longer prefix on your secondary connection
Reveal correct answer
Correct answer: C
Explanation
Correct option:
Configure your customer gateway to advertise the same prefix with the same Border Gateway Protocol (BGP) attributes on both public virtual interfaces
AWS Direct Connect links your internal network to an AWS Direct Connect location over a standard Ethernet fiber-optic cable. One end of the cable is connected to your router, the other to an AWS Direct Connect router. With this connection, you can create virtual interfaces directly to public AWS services (for example, to Amazon S3) or Amazon VPC, bypassing internet service providers in your network path. An AWS Direct Connect location provides access to AWS in the Region with which it is associated.
When using Direct Connect to transport production workloads between AWS services, it's a best practice to create two connections through different data centers or providers. You have two options on how to configure your connections:
Active/Active – Traffic is load-shared between interfaces based on flow. If one connection becomes unavailable, all traffic is routed through the other connection.
Active/Passive – One connection handles traffic, and the other is on standby. If the active connection becomes unavailable, all traffic is routed through the passive connection.
To configure an Active/Passive connection using a public ASN:
Allow your customer gateway to advertise the same prefix (public IP or network that you own) with the same Border Gateway Protocol (BGP) attributes on both public virtual interfaces. This configuration permits you to load balance traffic over both public virtual interfaces.
Check the vendor documentation for device-specific commands for your customer gateway device.
Incorrect options:
Set up the customer gateway to advertise the longer prefix on your primary connection - While configuring an Active/Passive connection using a private ASN, you need to set up the customer gateway to advertise the longer prefix on your primary connection. So this option is incorrect for the given use case.
Set up the customer gateway to advertise the longer prefix on your secondary connection - While configuring an Active/Passive connection using a private ASN, you need to set up the customer gateway to advertise the longer prefix on your primary connection. This option has been added as a distractor.
Active/active configuration from a public virtual interface is not supported using public ASN - If you're using a private ASN, load balancing on a public virtual interface is not supported. Active/active configuration from a public virtual interface is indeed supported using public ASN. So this option is incorrect for the given use case.
References:
https://docs.aws.amazon.com/directconnect/latest/UserGuide/Welcome.html
https://aws.amazon.com/premiumsupport/knowledge-center/dx-create-dx-connection-from-public-vif/
Discussion
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