Which site will AWS choose to reach your network?
Question
Your company has the following Direct Connect and VPN Connections Site A - VPN 10.1.0.0/24 AS 65000 65000 Site B - VPN 10.1.0.252/30 AS 65000 Site C - Direct Connect 10.0.0.0/8 AS 65000 Site D - Direct Connect 10.0.0.0/16 AS 65000 65000 65000 Which site will AWS choose to reach your network?
Answers
Explanations
Click on the arrows to vote for the correct answer
A. B. C. D.Answer - B.
AWS uses the most specific route in your route table that matches the traffic to determine how to route the traffic (longest prefix match)
Hence the one that matches this is Site.
B.For more information on route table priority, please visit the below URL:
http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_Route_Tables.html#route-tables-priorityAWS uses the Border Gateway Protocol (BGP) to exchange routing information with on-premises routers over Direct Connect and VPN connections. BGP uses the Autonomous System Number (ASN) to identify the different networks and route traffic between them.
In this scenario, we have four sites with different network configurations:
- Site A has a VPN connection with the IP range 10.1.0.0/24 and ASN 65000
- Site B has a VPN connection with the IP range 10.1.0.252/30 and ASN 65000
- Site C has a Direct Connect connection with the IP range 10.0.0.0/8 and ASN 65000
- Site D has a Direct Connect connection with the IP range 10.0.0.0/16 and ASN 65000 65000 65000
When AWS receives traffic destined for the IP range of your network (10.0.0.0/8), it will check the BGP routing tables to determine the best path to reach that network.
AWS selects the path with the longest prefix match, which means the path with the most specific IP range that matches the destination IP address. In this case, Site D has the longest prefix match for the IP range of your network (10.0.0.0/16), so AWS will choose Site D to reach your network.
Therefore, the correct answer is D. Site D.
