The Link Layer Discovery Protocol (LLDP) is a vendor-neutral protocol used by network devices to advertise their identity, capabilities, and neighbors on a LAN. The show lldp neighbors command on a RUCKUS ICX switch displays a summary of the information received from directly connected LLDP-enabled devices. This output specifically includes the "System Name" (hostname) of each neighboring device, making it the correct command to discover this information.

B. show chassis: This command displays hardware information about the local switch itself, such as its serial number, power supplies, and fan status, not information about attached devices.

C. ping: This is a Layer 3 utility used to test IP reachability to a known IP address or hostname. It does not discover the names of unknown attached devices.

D. show inline power: This command displays the Power over Ethernet (PoE) status for switch ports, including power allocation and consumption, not the system name of the connected device.

1. RUCKUS FastIron Command Reference Guide, 8.0.95:

Page 1519, "show lldp neighbors": This section describes the command and provides sample output. The output table explicitly includes a "System Name" column, which "Displays the system name of the neighbor device." This directly supports answer A.

Page 2011, "show chassis": This section details the command, stating it "displays information about the chassis, including the card cage type, serial number, and power supplies." This confirms the command is for the local device, making B incorrect.

Page 2067, "show inline power": This section describes the command's function to display "information about inline power." This confirms D is incorrect.