When a host establishes a telnet connection with the router attached to interface G0/0/0, the destination MAC address of a frame sent by the host will be the MAC address of the router interface G0/0/0. This is because the host needs to communicate with the router directly and uses the router's interface MAC address for frame forwarding. The destination IP address of a packet will be the IP address of the router's interface G0/0/0, as the telnet session targets this specific interface.