- 01Getting Started
- 02Understanding the Operating Modes of Network Devices
- 03Entering Privileged EXEC Mode with enable
- 04Entering Configuration Mode with configure terminal
- 05Renaming the Switch with hostname
- 06Moving Between Modes with exit and end
- 07Entering Port Configuration with interface
- 08Enabling a Port with no shutdown
- 09Assigning an IP Address with ip address
- 10Labeling a Port with description
- 11Viewing the Configuration with show running-config
- 12Listing Interfaces with show ip interface brief
- 13What Is a VLAN? Splitting a Network Logically
- 14Creating a VLAN with vlan
- 15Naming a VLAN with name
- 16Setting the Port Type with switchport mode
- 17Assigning a Port to a VLAN with switchport access vlan
- 18Listing VLANs with show vlan brief
- 19Adding a Static Route with ip route
- 20Viewing the Routing Table with show ip route
- 21Testing Reachability with ping
- 22Tracing the Path with traceroute
- 23Checking OS Information with show version
- 24Checking the Time with show clock
- 25Saving the Configuration with copy running-config startup-config
- 26Saving with write memory (the Short Form)
- 27Setting a Login Message with banner motd
- 28Configuring the Console Line with line console 0
- 29Setting a Password with password
- 30Requiring the Password at Login with login
- 31Configuring Remote Access with line vty 0 4
- 32Creating an Access List with access-list
- 33Checking Access Lists with show access-lists
- 34Viewing the MAC Address Table with show mac address-table
- 35Discovering Neighbors with show cdp neighbors
- 36Viewing the ARP Table with show arp
- 37Understanding Loop Prevention with spanning-tree mode
- 38Rebooting the Device with reload
- 39Hands-On: Configure a Small Office Network
Discovering Neighbors with show cdp neighbors
When you want to identify the Cisco device at the far end of a cable without tracing the cable, use show cdp neighbors. It displays information about directly connected neighboring Cisco devices, gathered via CDP (Cisco Discovery Protocol).
The syntax is show cdp neighbors, in privileged EXEC mode.
Running show cdp neighbors lists each neighbor's hostname, the local and remote ports of the link, and the device type.
A common stumble is a device where CDP has been disabled — then nothing shows up at all. Confirm CDP is enabled before drawing conclusions.
In real work, it is invaluable for quickly mapping the physical topology of a messily cabled network.
🧑💻 You can type this command into the Networking pseudo terminal to try it yourself (this page itself has no interactive terminal).