Which method is NOT a way to connect an on-premises network to OCI?

The method that is not a way to connect an on-premises network to Oracle Cloud Infrastructure (OCI) is Direct Connect. In the context of OCI, the available methods for establishing a connection between an on-premises network and the cloud include VPN Connect, OCI FastConnect, and Private Peering.

VPN Connect utilizes a secure IPSec VPN tunnel to create a connection over the public internet, allowing for encrypted data transfer between on-premises networks and OCI. OCI FastConnect provides a dedicated, high-bandwidth, and low-latency connection that bypasses the public internet altogether, enhancing performance and security.

Private Peering, typically used in conjunction with OCI FastConnect, allows organizations to establish connections directly from their private network into OCI, facilitating communication without exposing data to the internet.

In contrast, Direct Connect is a term often used in the context of other cloud providers, such as AWS, rather than OCI. Therefore, it does not apply as a method for connecting an on-premises network to OCI and is the correct choice as the method that does not exist in OCI's connectivity options.