Hi, and welcome to the fifth network application of this course, again, I'm convinced you're going to enjoy building, analyzing and testing this application as well, since it can prove to be very useful for a network administrator monitoring one or more of the switches or routers in the network. Actually, to understand our goal for this application better, let's assume you're a network admin, and you want to monitor any configuration changes that might occur on one of your core switches in the network. Of course, you have a lot of work to do, and don't have the time to log into the device, extract the running configuration, and manually compare it with the one from yesterday. Let's say instead, you would like a Python script to connect to your core network device over SSH. Extract the running configuration and save it to a file. The next day.

You want the script to perform the same task and save the configuration to a new file, then comparing the two files line by line character by character, and then send you an email highlighting all the changes that have occurred over the past 24 hours. Maybe some other administrator or who knows maybe a hacker logged into the device and performed some changes. Using the application that we're going to build. In this section. You as a network engineer or admin will automatically get notified via email about any configuration changes that have occurred on the device, thus saving time and efforts when monitoring your network. So the first thing we're going to do is to install the net Miko module, which we're going to use for the first time in the course.

Net, Miko works similarly to our SSH connection application from earlier in the course, and will take care of connecting to the Arista device logging in using the username and password, sending the show running command and storing the output. After the net Miko module does its job. We will identify the configuration file we saved on the previous day to our Ubuntu file system inside it Dedicated directory. The naming convention for our configuration files is going to be IP underscore date so that we can clearly identify the device and the date that configuration file has been saved. Next, it's time to connect to the device, retrieve the running configuration and write it to a file with a similar naming convention, but with the date of today, and then compare the two files using the diff lib module that we're going to see later. In this section, we're going to generate an HTML output to compare the contents of the two files instead of plain text for better readability.

Finally, we're going to write the results in HTML format inside an email and then send it to the email address of the network administrator in a nice and clean format. Of course, since I said that we want this task to be automatically performed on a daily basis. We are going to configure our Ubuntu machine to run this script every day and notifies the network admin of any configuration changes made on the device during the last 24 hours. As always, you can find the entire code of this application in the last lecture of this course section. So feel free to download it now and follow my code analysis in the next videos, or even better, write the code yourself as we go through each lecture that follows. So I hope this sounds cool and interesting.

Let's get to work and I'll see you in the next lecture.