CCNA to CCNP Transition: Working with Passwords and Telnet

Learn about tricky and confusing subjects in the CCNA Curriculum such as how to work with passwords and Telnet

*** Part of the Complete Course: Cisco CCNA to CCNP Transition ***

Whenever I taught  CCNP in the class-room, I found that Students were confused about some topics or commands that they have studied in the CCNA course (with someone else!), and I had to clarify or re-explain these topics or commands to them. This is because these topics or commands are confusing by their nature, or because the way that they are typically explained to the students. Therefore, the idea of this course came in my mind, which intend to clarify those confusing topics or commands.

This course contains two sections:

1. Working with Passwords: which contains thoughts on passwords, understand the meaning of the no service-encryption command, and how to break the type 7 encryption.

2. Working with Telnet: which contains how to work with telnet as source or destination, and how to telnet to a specific port.

3. Network Attacks Using Features of the IP Protocol: where different network attacks that uses features of the IP protocol are explained, including the IP Smufing attack.

For example, when working with passwords: why do we have two ways to configure the enable password? and why both passwords used in these two ways must be different? Also how can we use the question mark as part of the password? Did you ever try to configure a password like that one?

Another thing is does the no service password-encryption command disable encryption for current or future passwords? or may be both? And how can we break the type 7 encryption, so the encryption configured by the service password-encryption command?

And for Telnet, we will see multiple ways of working with telnet as both the source and the destination, so how to return back to the original host without disconnecting the connection, how to show incoming connections on the destination and the outgoing connections on the source , and also the multiple ways of clearing these connections on either the source or the destination. Finally, we will see how to telnet to a specific port, so to check if BGP or HTTP are working on the remote host for example.

As for the network attacks, the IP Smufing attack was explained and demonstrated practically, which takes advantage of the IP directed broadcast feature, and the ways of mitigating this attack were also explained in practical manner.