Cisco CCNA

The Cisco CCNA Discovery Protocol (CDP) sure looks simple enough, but there are quite a few details to know for success on the Cisco CCNA exam. In yourCisco CCNA studies, you’ll be introduced to additional uses for Cisco CCNA CDP, but for now it’s enough to know that Cisco CCNA CDP is designed to give you information regarding directly connected Cisco CCNA routers and Cisco CCNA switches.

Cisco CCNA CDP runs by default between all directly connected Cisco devices. CDP is also a Cisco CCNA protocol - if the directly connected device is not a Cisco device, you won’t see the information you wanted.

The basic Cisco CCNA CDP command to display information about the directly connected neighbor is “show cdp neighbor”.

R2#show cdp neighbor Cisco CCNA

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge Cisco CCNA

S - Switch, H - Host, I - IGMP, r – Repeater

Device ID Local Intrfce Holdtme Cisco CCNA Capability Platform Port ID

R1 BRI0 167 R 2521 Dialer1

This command is particularly helpful when troubleshooting Cisco CCNA switches. There’s no need to trace wiring in a rack of Cisco CCNA devices to see what routers are connected to a Cisco CCNA switch when show cdp neighbor can be used. In the above output, you can see the remote device’s hostname, what interface on the remote device is connected to the local device, the capability of the remote device, the remote device’s hardware platform, and the local interface that is connected to the remote device.Cisco CCNA

CDP can be disabled at both the global and interface level. To disable CDP at the interface level, run no cdp enable on the interface, and cdp enable to turn it back on Cisco CCNA.

cdp timer defines how often CDP packets are transmitted, and cdp holdtime defines how long a device will hold a received packet.Cisco CCNA

To turn CDP off for the entire router, run no cdp run. To view the current global status of CDP, run show cdp.
One of the major topics on your Cisco CCNA and CCNP exams is Frame Relay. Additionally, Frame Relay is one of the most popular WAN technolgies in today’s networks. Getting hands-on experience with Frame Relay in Cisco networks isn’t just a good idea, it’s a necessity. Let’s face it, your employer is going to get a little touchy if you start experimenting with your network’s Frame Relay setup.

To practice all your important Frame Relay commands for your exams, you need a working Frame Relay cloud in your home lab. A production network’s Frame cloud consists of a lot of Frame switches, but if you choose wisely, a single Cisco router can act as your home lab’s entire Frame cloud!

Before we look at the configuration of such a Cisco CCNA router (hereafter referred to as a “frame relay switch”), let’s look at the physical requirements.

The more serial ports you have, the better. You should get a router with at least four serial ports. For frame switching purposes, it doesn’t matter if the ports are synchronous or asynchronous - you just need the ports.

You will also need some Cisco CCNA DTE/DCE cables. The Cisco CCNA DCE end of the cables will be connected to the frame switch.

A great configuration for a CCNA practice lab is three routers that serve as “production” Cisco CCNA routers, and a 4th router as a frame relay switch. (You’ll want an access server as well, but that’s another article.)

What I use in my student and customer pods is a setup where R1 is connected to the frame switch’s S1 port, R2 is connected to S2 on the frame switch, and R3 is connected to the frame Cisco CCNA switch’s S3 port.

Now comes the tricky part - the configuration. A frame relay switch’s config can be hard to find, so here’s a copy of mine. Pay particular attention to the config on ports Cisco CCNA s1, s2, and s3.

Here are just SOME of the Cisco CCNA Topics we Cover in our website.

Cisco CCNA Training Videos:   Differences between Routers, Switches and Bridges OSI Model Explanation - Crucial for the Cisco CCNA Exam. Learn How a Switch Works and Builds the MAC Table Setup VLANs on a Cisco Switch
Learn how the Spanning Tree Protocol (STP) works Configure VLAN Trunking Protocol (VTP)
Setup Static Routing on Multiple Routers to Create a Network Learn How to Configure Frame Relay on Cisco Routers
Use RIP to Automate the Creation of Routing Tables Learn why IGRP is used on Cisco Router Networks
Setup and Configure OSPF Configure Access Lists to block unwanted traffic Detailed Instruction on Binary Numbers and Subnetting  …This is Just the Beginning!!!

Preface

This document is my experience in practice. If there are some erros,please contract me Cisco CCNA Website:http://ciscoccna.net/about/. Thankyou for your help.

Nor is there any guarantee that the information contained in this document is accurate. It is offered in the hopes of helping others, but you use it at your own risk. The author will not be liable for any damages that occur as a result of using this document.

Conventions

Important terms and concepts, when they are introduced, may be displayed in bold. Commands included in the body of the text will be displayed in this font. All names and addresses used in examples are just that, examples, and should not be used on your network. Do not type them in verbatim when configuring your system. Finally, in some examples where the command rquires an IP address as an argument, the IP address may be represented in this way, xx.xx.xx.xx, or aa.bb.cc.dd. You will never actually use these strings when configuring your system. They are mearly a convention of this document to specify that you should substitute the appropriate IP address at that point.