What is the main characteristic of virtual trunks?

The main characteristic of virtual trunks is that they are independent of physical hardware. Virtual trunks allow for logical connections that do not rely on specific physical cabling or connections. This independence means that virtual trunks can be configured and managed through software, allowing greater flexibility in network design and the ability to adapt to changing requirements without being constrained by the limitations of physical infrastructure. This characteristic enhances scalability and simplifies management, as multiple virtual trunks can be established over the same physical network without the need for additional hardware modifications.

In contrast, connectivity through hardware only would imply a reliance on physical connections, which does not align with how virtual trunks operate. The statement that they are always encrypted for security suggests a security feature that is not inherent to the core function of a virtual trunk, as encryption is an additional aspect that can be applied but is not a defining characteristic. Saying that they are compatible exclusively with legacy systems incorrectly limits their application, as virtual trunks are designed to work with modern networking environments and systems.