In the output of show ip interface brief, what state will switch interfaces be in when connected to another device?

In the context of the show ip interface brief command output on a Cisco switch, when interfaces are connected to another device and functioning properly, their state will be "up/up." This indicates that both the line protocol and the physical interface are operational.

The "up" status signals that the interface has been enabled and is actively participating in the network. This occurs when there is a valid connection between the switch and another device, such as another switch, router, or endpoint. The presence of a proper link, typically formed by suitable cabling and proper configuration on both ends, allows the interface to be operational.

Moreover, the line protocol being "up" suggests that the data link layer is functioning correctly. In Ethernet-based networks, this often means that the physical connection is established, and the protocols required for communication at the data link layer are also active, allowing for data transmission.

In summary, the "up/up" state is indicative of a healthy, working interface that is connected to another device and ready to transmit and receive data.