When a systems administrator needs to access a hypervisor and the default RDP port (3389) is blocked by company policy, the administrator can use an alternative method. One common alternative is using SSH:

Port 22: This is the default port for SSH (Secure Shell), which is commonly used for secure remote access to servers and hypervisors, especially in Unix/Linux environments.

Port 23: This is the default port for Telnet, which is an unsecured protocol and generally not recommended for remote access due to security concerns.

Port 80: This is the default port for HTTP, used for web traffic, not remote access.

Port 3090: This is not a standard port for remote access protocols.

Using SSH (port 22) is a secure and widely accepted method for remote management of servers and hypervisors.