A company's network engineer is designing an active-passive connection to AWS from two on- premises data centers. The company has set up AWS Direct…

To control outbound traffic from AWS over AWS Direct Connect and establish an active-passive configuration, BGP community tags are used. The 7224:7300 tag signals a high preference, while 7224:7100 signals a low preference. By advertising prefixes from the primary data center with the high preference tag (7224:7300) and prefixes from the failover data center with the low preference tag (7224:7100), the network engineer instructs the Direct Connect gateway to prioritize the path to the primary data center. Traffic will only be sent to the failover data center if the primary path becomes unavailable.

A. This configuration incorrectly sets the primary data center to low preference and the failover to high preference, making the failover path the active one.
C. The 9xxx series BGP community tags are used for local preference on private VIFs, not for influencing routing preference from a Direct Connect gateway with transit VIFs.
D. This option also uses the incorrect 9xxx series BGP community tags for a Direct Connect gateway scenario.

1. AWS Documentation, AWS Direct Connect User Guide, "Routing policies and BGP communities". This page explicitly lists the supported BGP communities for influencing routing.

2. AWS Documentation, AWS Direct Connect User Guide, "BGP communities for routing policies". It specifies: "For prefixes from an AWS Region, you can apply the following BGP communities: 7224:7100 – Low preference, 7224:7200 – Medium preference, 7224:7300 – High preference."

3. AWS Documentation, AWS Direct Connect User Guide, "Use BGP communities to influence the routes advertised and received over a public VIF". While this example is for a public VIF, the community tags for preference (7100, 7200, 7300) are applicable to Direct Connect gateway routing as well, as confirmed in the primary reference.