When the administrative mode of SW1 G0/0 is dynamic auto and SW2 G0/0 is set to trunk, what is the operational mode of SW1 G0/0?

When examining the scenario where SW1's G0/0 port is set to dynamic auto and SW2's G0/0 port is configured as trunk, it's important to understand how the Dynamic Trunking Protocol (DTP) operates. In this case, SW2’s port, being set to trunk, actively negotiates to establish a trunk connection with connected devices.

The dynamic auto mode on SW1's G0/0 allows that port to respond to DTP negotiations. Since the port on SW2 is configured as trunk, it will send out DTP frames to negotiate the connection type. The interaction between these two settings leads to SW1's G0/0 port transitioning to trunk mode as it responds favorably to SW2’s request for trunking.

Thus, SW1 G0/0, in this situation, will successfully establish a trunk link with SW2 and operate in trunk mode. This is appropriate because the device is able to open up a trunk link through DTP negotiation established by the port on SW2 that is explicitly requesting a trunk configuration.