1Z0-1072-25 Question 167
Single answerYou have set up a Database subnet and an Application subnet within the same VCN in Oracle Cloud Infrastructure. A compute instance in the Database subnet cannot connect to the load balancer in the Application subnet. You run Network Visualizer to investigate and see a 'Route Table Mismatch' warning in the visualized path. Which action should you perform to fix and restore connectivity?
- A
Update the route table for the Database subnet to add or correct the route to the Application subnet.
- B
Configure a service gateway in the VCN to directly route traffic between the Database subnet and the load balancer.
- C
Modify the load balancer's security list to permit traffic from the Database subnet on all ports.
- D
Enable an Internet Gateway for the Database subnet to allow public traffic to reach the load balancer.
Show answer and explanation
Correct answer: A
Explanation
In Oracle Cloud Infrastructure, Network Visualizer flags issues and clarifies routing paths between subnets. A 'Route Table Mismatch' typically indicates that routing rules are incorrect or missing. Updating the route table in the originating subnet (in this case, the Database subnet) ensures that packets can reach the load balancer in the Application subnet. For more details, see the official Oracle Cloud Infrastructure documentation on diagnosing VCN routing issues using Network Visualizer.
- A. Correct.
Correct. The Network Visualizer warning indicates that the Database subnet's route rules are not correctly pointing to the Application subnet or its associated gateway. By updating or correcting the Database subnet's route table entry (for example, specifying the load balancer's subnet or gateway as the next hop), you ensure packets can be routed properly.
- B. Incorrect.
Incorrect. A service gateway is used to connect to Oracle services (like Object Storage) without traversing the internet. It is not intended to directly route traffic between two subnets in the same VCN.
- C. Incorrect.
Incorrect. Security lists control inbound/outbound permitted traffic but do not resolve route table issues. Even with correct security rules, the routing still needs to be accurate in the Database subnet's route table.
- D. Incorrect.
Incorrect. Enabling an Internet Gateway for the Database subnet unnecessarily sends traffic out to the public internet. Traffic between a Database subnet and an internal load balancer should remain inside the VCN. This does not solve the route mismatch.