Cover

Table of Content

1. Making a list of Network Topology using CDP.

  • CDP
  • CDP holdtime
  • CDP neighbors details

2. How to set a Network Monitoring tool or Netflow collector

  • NetFlow collector
  • Ingress and egress ports
  • Steps to avoid an error

3.How to use Telnet

  • VTY password
  • Telnet connections
  • Connected users
  • Closing sessions

4.Link Layer Discovery Protocol (LLDP)

  • LLDP

5.Exploring Connected Devices Using CDP and LLDP

  • LLDP holdtime
  • LLDP neighbors details

6. How to reset Cisco Password

  • Rommon mode
  • Confreg 0x2142
  • enabling new password
  • Steps to avoid errors

7.How to resolve hostnames

  • Building a host table in a router
  • telnet login failed with hostname
  • Steps to avoid  login errors

 

 

 

 

 

Network With Practical Version 2

Making a list of Network Topology using CDP.

CDP stands for Cisco Discovery Protocol. It is a Cisco proprietary Layer 2 protocol to help administrators collect information about locally attached Cisco devices. Armed with CDP, we can gather hardware and protocol information about directly connected devices, which is crucial information to have when troubleshooting and documenting the network. Another dynamic discovery protocol is the Link Layer Discovery Protocol (LLDP), it is not a proprietary of any vender.

Let’s start by exploring the CDP timer and CDP commands we’ll need to verify our network.

If you run show CDP command on router or switch. It will give you two CDP global parameters that can be configured on Cisco devices. Cisco switch and router both use the same parameters.

1. CDP timer delimits how often CDP packets are transmitted out all active interfaces.

2. CDP hold time delimits the amount of time that the device will hold packets received from neighbor devices.

As I created a small topology that is given below in the picture. I use sho CDP command on Lucknow Router (in the pic). Cisco device sends a packet every 60 seconds to its neighbor devices and receives the same from them. It also shows the hold time value that is 180 seconds. Third line sending CDPv2 advertisements is enabled which means CDP neighbors are enabled in these devices.

We can use the global commands CDP hold time and CDP timer to configure the CDP hold time and timer on a router if necessary like this.

 

Lucknow(config)#cdp ?

advertise-v2 CDP sends version-2 advertisements

hold time Specify the hold time (in a sec) to be sent in packets

Impressum

Verlag: BookRix GmbH & Co. KG

Texte: Mulayam Singh
Bildmaterialien: Adarsh Gupta
Cover: Sharad Singh
Lektorat: Nishchal Agrahari
Übersetzung: Mitesh Srivastav
Satz: Mulayam Singh
Tag der Veröffentlichung: 18.10.2019
ISBN: 978-3-7487-1816-1

Alle Rechte vorbehalten

Widmung:
There are many people who work to put a book together, and as an author, I dedicated an enormous amount of time to write this book, but it would have never been published without the dedicated, hard work of many other people.

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