A large electric appliance company uses two AWS Direct Connect links from two different routers for connecting to AWS & uses the Amazon S3 bucket to save all user data. Amazon S3 bucket is created based upon various departments within this company & each of these departments has a unique IP pool assigned to its users by the local IT team. Recently this company has acquired another firm that also needs access to the Amazon S3 bucket to save their users` data. IT Team has completed routing of CIDR range of new firm to AWS Direct Connect over both BGP peering. Post this addition of prefixes, BGP Peering with AWS is showing down.Which of the following can resolve this issue?

Answer options:

A.BGP Community Tags need to be added for new prefixes.
B.Since the ASN of the new firm is the same as that of AWS, as-override needs to be added in BGP peering.
C.Open an AWS Support ticket to add new prefixes inbound direction at AWS end.
D.Reduce the number of BGP prefixes below 1000.

Correct Answer – D
There is a limit to the number of BGP prefixes advertised on AWS Direct Connect peering. If the number of BGP prefixes advertised is more than 1000, it will shut down BGP peering impacting all existing traffic. To resolve this issue, check the number of BGP prefixes advertised to AWS & ensure that count is less than 1000 prefixes.
Option A is incorrect as missing BGP community tags will not shut BGP peering.
Option B is incorrect as with the same ASN, prefixes will not be advertised to AWS, but it will not shut BGP peering.
Option C is incorrect as the opening of the AWS Support ticket is not required for the addition of new prefixes at the AWS end. All BGP prefixes less than 1000 prefixes are accepted at the AWS end.
For more information on BGP limits for AWS Direct Connect Links, refer to the following URL under section "Prerequisites for Virtual Interfaces".
https://docs.aws.amazon.com/directconnect/latest/UserGuide/WorkingWithVirtualInterfaces.html