Today, I studied about the Cisco Discovery Protocol or CDP for short. Honestly, I’ve never used the command before. I guess I never have had to because I’ve always set up my own local networks and have had physical access to equipment to see what interface a cable was plugged into and stuff like that. But I suppose if you were dealing with a WAN you might not have that convenience and need to use CDP. Below are some of my notes about CDP.
CDP – Cisco Discovery Protocol
Basically CDP finds information about all the neighboring Cisco devices. Information that CDP provides includes:
- The host name
- Network Addresses
- Port names like S0/0 or E0/0
- What the device can do. Ex: router
- The Platform of the device. Ex: 2600 Series Router
CDP is proprietary. Meaning that only Cisco routers and switches use it.
CDP uses the data link layer to talk to other Cisco devices.
CDP starts automatically at boot time.
CDP Commands:
- Show cdp entry
- show cdp interface
- show cdp neighbors
- show cdp traffic
To turn On/Off CDP Globally:
- cdp run
- no cdp run
To run On/Off CDP on an Interface:
- cdp enable
- no cdp enable
Answers in the back of the book are not correct
In the chapter 6 text of the Cisco book that I’m reading it states:
The command ‘show cdp neighbors detail’ is the same as ‘show cdp entry *’
The Review Question #6 at the end of the chapter:
Which Cisco IOS command produces the same result as the show cdp neighbors detail command
a. show cdp traffic
b. show cdp entry *
c. show cdp neighbors
d. show cdp interface all
However the answer in the back of the book says that the correct answer is ‘c’ when it should be ‘b’.
I wonder If I just have an older version of the book and maybe the new version has been updated, but anyway it makes it hard to study when the answers in the back are wrong. I think there might be a few more, but I can’t remember which ones off the top of my head right now.
Day 27 Summary
Even though I’ve been working on a ton of other homework I have, I was able to put in some study time for my ICND1 Exam next week and learned all about CDP which I didn’t really know a whole lot about. I receive my tax return today, so I scheduled my exam for Thursday, Feb 11 @ 9am! I’m very fortunate I got my tax return back otherwise I don’t know how I would have been able to pay for another exam.
Thanks for everyone’s support!
and Good luck to everyone who is also studying for the exam!
-Blake
Related Topics:
ICND1 Study Guide – The Fastest Way To Get Cisco Certified Guaranteed!