show cdp neighbors ” Displays information regarding the Layer 1, 2, and 3 information about connected neighbors.
The show interface status explanations , which are displayed in the first line of the output:
Ethernet 0 is up ” The "Up" descriptor indicates the physical link is connected and is live.
Ethernet 0 is down ” The "down" descriptor indicates that the link is not connected to another functioning device or there is a problem with the interface or cabling.
Ethernet 0 is administratively down ” The "administratively down" descriptor means that the shut down command was used on the interface.
Ethernet 0 is disabled ” The "Disabled" descriptor indicates that the interface has received more than 5,000 errors in a keepalive interval, which is 10 seconds by default.
Line protocol is up ” This indicates that keepalives are successful and that the software controller for the interface believes the interface is usable with a protocol such as IP.
Line protocol is down ” This indicates that keepalives for the current protocol used on the interface are not being received or do not match the current configuration.
show controller device ” Displays the errors and memory handling for a selected device.
clear counters interface ” Clears the counters for the listed interface.