What does the output of the show ip interface brief command NOT include?

The output of the "show ip interface brief" command provides a concise summary of the IP-related information for interfaces on a router or switch. Specifically, it includes details such as the assigned IP addresses for each interface, along with the status of both the interfaces and the protocols they are running.

One important aspect to note is that while this command provides useful quick information regarding IP configurations, it does not display the MAC addresses associated with the interfaces. The MAC address is a Layer 2 address that relates to the data link layer, whereas the command focuses primarily on Layer 3 (network layer) information, which involves IP addressing and status. Hence, the omission of MAC addresses from the output aligns with the command's purpose of presenting a summary of interface status and configuration rather than complete hardware details.

By knowing what the command includes and does not include, you can effectively troubleshoot and manage network interfaces. This understanding is key for network operations and configuration validation.