A network administrator is unable to switch between VDCs. What will cause this problem?

The `network-admin` role has the highest level of administrative privileges in Cisco Nexus VDCs, allowing the user to switch between VDCs and manage global VDC operations.

The `vdc-operator` role in Cisco Nexus VDCs is specifically designed with limited privileges that restrict the user to a single VDC. This role allows operation within a VDC but does not grant the necessary permissions to switch between different VDCs or manage VDCs at a global level.

The `network-operator` role generally has read-only access and cannot make configuration changes, nor does it typically grant the ability to switch between VDCs.

Logging in as a generic user like 'cisco' without specified roles or permissions would generally not grant VDC switching capabilities, unless 'cisco' was assigned a privileged role like network-admin, which is not implied.