1Z0-1072-25 Question 65
Select 2You are designing a multi-tier application on Oracle Cloud Infrastructure (OCI) with a load balancer in a public subnet and application servers in a private subnet. To support multiple services on each application server, you plan to attach a secondary VNIC or add secondary private IP addresses to the existing VNIC. You also want the option to make one of the services public-facing by assigning it a public IP address. Which two statements about private and public IP addresses on OCI VNICs are correct in this scenario?
- A
- A single VNIC can have multiple private IP addresses, but only the primary private IP address can be assigned any type of public IP.
- B
- You can add additional private IP addresses to a secondary VNIC if it is attached to the instance and placed in the correct subnet.
- C
- Once a private IP address is assigned to a VNIC, it remains permanently tied to that VNIC even if the instance is terminated.
- D
- A reserved public IP address can be assigned to either the primary or any secondary private IP address of a VNIC.
- E
- A single private IP address can be moved across VNICs in different Availability Domains, even if they belong to different VCNs.
Show answer and explanation
Correct answers: B, D
Explanation
In Oracle Cloud Infrastructure, VNICs can hold multiple private IP addresses, and reserved public IPs can be assigned to any private IP on a VNIC (primary or secondary). Ephemeral public IPs, however, must be assigned only to the primary private IP. Private IPs are typically released when an instance is terminated or the VNIC is detached, but you can reassign private IPs within the same subnet or VCN. For more details, refer to Oracle's OCI documentation on VCNs, subnets, public IP addresses, and VNIC configurations.
- A. Incorrect.
Option 1 is incorrect. While a single VNIC can indeed have multiple private IP addresses, you can also assign a reserved public IP to secondary private IP addresses. Only ephemeral public IP addresses must be on the primary private IP, but reserved public IP addresses can be assigned to secondary addresses.
- B. Correct.
Option 2 is correct. You can attach a secondary VNIC to the same instance, or add additional private IP addresses to an existing VNIC. As long as the secondary VNIC or the added private IP is in the correct subnet and attached to the instance, it can support multiple services.
- C. Incorrect.
Option 3 is incorrect. By default, when you terminate the instance or detach a VNIC, the private IPs associated with that VNIC are released. You can move private IP addresses to different VNICs within the same subnet, but they do not remain permanently tied after instance termination unless you explicitly reassign them.
- D. Correct.
Option 4 is correct. A reserved public IP address can be assigned either to the primary or any secondary private IP on a VNIC, offering flexibility when you need to make different services publicly accessible.
- E. Incorrect.
Option 5 is incorrect. Even if the subnet is regional, you cannot move a private IP address to completely different VCNs, and you must remain within the same subnet. Although you can move a private IP between VNICs across Availability Domains if the subnet is regional, you cannot move it to a subnet in a different VCN.