These are the protocols that should be used to share the disks between the nodes of a database cluster to access the same LUN (Logical Unit Number). A LUN is an identifier that represents a logical unit of storage, such as a disk, partition, volume, etc., that can be accessed by a host system or device. To share the disks between the nodes of a cluster, the following protocols can be used:
iSCSI (Internet Small Computer System Interface): This is a protocol that allows SCSI commands to be sent over IP networks. iSCSI can enable block-level storage access over a network, which means that the host system or device can access the storage as if it were a local disk.
FC (Fibre Channel): This is a protocol that provides high-speed and low-latency data transfer over optical fiber cables. FC can also enable block-level storage access over a network, which means that the host system or device can access the storage as if it were a local disk.

NAC (Network Access Control) is a technology that will limit access to authorized individuals and ensure the system that connects to the environment meets patching, antivirus, and configuration requirements. NAC can enforce policies and rules that define who, what, when, where, and how a device or a user can access a network or a cloud environment. NAC can also inspect and evaluate the security posture and compliance status of a device or a user before granting or denying access. For example, NAC can check if the device has the latest patches, antivirus software, and configuration settings, and if not, it can quarantine, remediate, or reject the device. NAC can also monitor and audit the ongoing network activity and behavior of the devices and users, and take actions if any violations or anomalies are detected.

Regression testing is a type of software testing that verifies that existing features or functionalities of a system or application are not affected by any changes or updates made to it. Regression testing can help assess whether all the known bugs and fixes are applied and unwanted ports and services are disabled when reviewing a new application implementation document for a cloud deployment, as it can detect any errors or defects that may have been introduced or re-introduced after applying patches, updates, or configurations to the application. Reference: CompTIA Cloud+ Certification Exam Objectives, page 19, section 4.1

The inbound rule that the security team identified as a potential vulnerability is the one that allows SSH access (port 22) from any source (0.0.0.0/0). This means that anyone on the internet can try to connect to the Linux servers using SSH, which poses a risk of unauthorized access or brute-force attacks. The cloud administrator, who is working remotely, logs in to the cloud management console and modifies the rule to set the source to "My IP". This means that only the administrator's IP address can connect to the Linux servers using SSH, which improves the security of the servers. However, this also prevents other authorized users, such as the internal developer, from accessing the servers using SSH, as they have different IP addresses than the administrator. Therefore, the administrator needs to modify the rule again to allow more sources for SSH access.
The best option for both the developer and the administrator to access the server from their locations is to modify the inbound rule to allow the company's external IP address as a source. This means that only the IP addresses that belong to the company's network can connect to the Linux servers using SSH, which reduces the attack surface and ensures that only authorized users can access the servers. The company's external IP address can be obtained by using a web service such as [What Is My IP Address?] or [IP Location]. The administrator can then enter this IP address or its CIDR notation in the source field of the inbound rule.

Checking in and committing are actions that save and update the changes made to a file or code in a version control system or repository. Checking in and committing can help track and synchronize the changes made by different users or developers working on the same file or code. The deployment script changes made by the first administrator were not checked in and committed is the most likely reason for the issue of the application load balancer being missing from the new deployment after a second administrator made some changes and ran the script. If the first administrator did not check in and commit the changes made to add an application load balancer to the script, then those changes would not be reflected or available in the latest version of the script used by the second administrator. Reference: CompTIA Cloud+ Certification Exam Objectives, page 13, section 2.5