|  | 4.3 | Router's Network Neighbors
| 4.3.4 | Showing CDP entries for a device and CDP neighbors
CDP was designed and implemented as a very simple, low-overhead protocol. A CDP frame can be small yet retrieve a lot of useful information about neighboring routers. You use the command show cdp entry {device name} to display a single cached CDP entry. Notice that the output from this command includes all the Layer 3 addresses present in the neighbor router, Router B. An administrator can view the IP addresses of the targeted CDP neighbor (Router B) with the single command entry on Router A. The hold-time value indicates the amount of elapsed time since the CDP frame arrived with this information. The command includes abbreviated version information about Router B. You use the command show cdp neighbors, as shown in Figure , to display the CDP updates received on the local router. Notice that for each local port, the display shows the following: neighbor device ID local port type and number decremental hold-time value, in seconds neighbor device capability code neighbor hardware platform neighbor remote port type and number To display this information as well as information like that from show cdp entry, you use the optional show cdp neighbors detail.