The technician should use port 22 to configure a server that requires secure remote access. Port 22 is the default port for Secure Shell (SSH), which is a protocol that allows secure remote login and command execution over a network connection using a command-line interface (CLI). SSH encrypts both the authentication and data transmission between the client and the server, preventing eavesdropping, tampering, or spoofing. SSH can be used to perform various tasks on a server remotely, such as configuration, administration, maintenance, troubleshooting, etc.

Explanation
The administrator should rebuild the volume to restore it after replacing the failed hard drive. A volume is a logical unit of storage that can span across multiple physical disks. A volume can be configured with different levels of RAID (Redundant Array of Independent Disks) to provide fault tolerance and performance enhancement. When a hard drive in a RAID volume fails, the data on that drive can be reconstructed from the remaining drives using parity or mirroring techniques. However, this process requires a new hard drive to replace the failed one and a rebuild operation to copy the data from the existing drives to the new one.
Rebuilding a volume can take a long time depending on the size and speed of the drives and the RAID level.

10.20.10.15 and 10.20.10.254 should be in the same subnet
255.255.255.0 must be the subnet mask.