Instead of routing network packets through the dual-homed instances, where should each dual-homed instance receive and process requests to fulfil his criteria?
On one of the web servers
On the front end
On the back end
Through a security group
Explanations:
The question states the setup is foreachweb server to connect to a mid-tier network. If the requests were processed ononeof the web servers, it would create a single point of failure and defeat the purpose of having multiple web servers.
In a dual-homed instance setup with distinct subnets (where routing is not the goal), each interface receives and processes requests intended for its respective subnet. The web server (front end) receives requests on its interface in the public subnet, and it uses itsotherinterface (in the mid-tier subnet) to communicate with the application server. This fulfills the dual-homed concept with each interface handling traffic for its respective network.
The back end (database or other downstream services) is not directly involved in the dual-homed setup as described. The dual-homing is about the web server’s connection to the mid-tier, not the back end.
Security groups control traffic flow (allowing or denying traffic), but they do notprocessrequests. The instances themselves process the requests they receive on their network interfaces.