As the last entry of the series, I thought it might be nice to have a reference of some of the most useful show commands, as they are of fundamental importance not only for the exam labs but in real world deployments as well. I will try to break them down into different sections, grouping the commands by area whenever possible.

This should not be considered a comprehensive list, but simply the show commands that you are more likely to be using more than others while preparing for the CCENT exam.

General show commands

  • show running-config (or show run): shows the whole current device configuration

Switching

  • show interfaces: a very detailed output with details about each interface on the device, with information including status, MAC address and packets transmitted/received
  • show mac-address-table: self-explanatory

Routing

  • show ip interface [ brief ]: shows a list of interfaces, the associated IP address and the status
  • show protocols: this lists what L3 protocols are running (i.e. what protocols are being routed – nowadays it’s mostly IP)
  • show ip protocols: what routing protocols are running
  • show ip route: shows the current routing table

CDP (Cisco Discovery Protocol)

  • show cdp neighbors [ detail ]: shows information about all the devices connected to the current device, with information like name, type of device and local interface
  • show cdp entry $entry: shows CDP information about a specific neighbor
  • show cdp interface $interface: shows CDP information about the specified interface

show cdp neighbors detail and show cdp entry * are equivalent and result in the exact same output.

There you go, I hope you found this series useful, and by all means please feel free to drop me a line in the comments with suggestions, feedback, requests for improvements or anything else. And good luck with the exam ;)