 Now that we have seen how to troubleshoot different layers. It's time to try it out. I have created a packet tracer simulation for you There are some bugs in it. Why don't you try to troubleshoot? That's looks that looks like a nice idea. Okay, let's try it out. Welcome back to Cisco packet tracer and the topic of troubleshooting So what Kavya has done is she has given us a Cisco packet tracer file and there are some Issues that are there in the networks that have been configured in that file It's the same file that we have been using till now here What we will try to do is try to look at how we can go ahead and find those errors or whatever the challenges are So she has said that she has given us three challenges and as as in when we complete one challenge We'll be going to the next one So what we'll try to do is we'll try to take the approach that we have been seeing of our Troubleshooting so we'll start with the physical error and then start going above So let's get into it and look at what is our first challenge? So our first challenge is that the students in the hostel are not able to access the institute server It's the day of the registration which is to be done on the institute server. This is the first challenge that we have Let's go to our Cisco packet tracer topology so right now we it looks like we are in the physical Topology mode and we see a hostel floor here. There is a Wi-Fi router. There is a PC We just connected via LAN. There is a phone and the laptop so physically this is how you will see the network and Though in Cisco packet tracer, you can also see it logically But in in the actual scenario this is just this will just be a diagram and you will not be able to you know Like here you see these lines and the Wi-Fi is connected. You will actually have to go on the laptop and check So let's go to the physical scenario and Maybe let's try with this PC so we know that the address of the Institute web server is 10 dot 10 dot 10 dot 10 and if we open the browser and try to open the web page using 10 dot 10 dot 10 dot 10 It says server reset connection Okay, so the first thing that we can do is Check the physical connectivity of the system. Okay, so if we can see the PC is connected here We can see this wire here. This is connected to this port and this port is in turn connected to the Server room, okay, and similarly this Wi-Fi is connected to the server room So one of the ways of checking this connectivity. I mean since it will not be feasible for you to trace the entire wire, so it becomes difficult to You know check all the wires and you know go run around the wire and see if it's connected or not So one of the ways you could also check this is using the ping command I mean if if you are able to successfully ping The system or in this case the gateway if the computer is connected to the gateway, that means the connection is fine So in case if that does not happen in that case, maybe we'll have to go back and start looking at the wire So let's first try to look at the gateway. So the gateway for this computer here is 172.1601 So let's go back to the desktop and Try to ping Oh, sorry not the terminal We need the command prompt So we what we have to type is PING 172.16.0.1 And we see our pings are successful. That means our PC is successfully connected to the gateway So till the gateway, there is no problem So why not just go ahead and try to see if we can connect to the server At least you have a connectivity with the server. So again, what we'll do is we'll use ping But this time we'll use the IP address of the server which is 10.10.10.10 And yes, the server is connected with us. That means At till the network layer We do not have any issues So we are able to successfully ping the server and it is replying back That leaves us that the issues could be on the Higher layers. So the issues are on the higher layer, which is the application layer So how can we check the application layer? So one of the things with the web server is at the application is the server running in the sense There is a particular program or a process which runs on the machine which tells us that the web server The service of the web server is running on the server. Okay So one of the things that we can do is go and check on the web server So let's close this and We'll go back to the logical one. It's easier to get to the server now So this is the hostile server and this here is the web server So if we Just want to confirm See the IP address is 10.10.10. So this is the server that we are trying to reach and it it is Connected to the the PC is connected to the server. The connectivity is fine But the problem is that the that particular service that is the web service is not running. Okay So let's go to services and so we have different services here And let's see HTTP. So what we see here is HTTPS is on but HTTP is off So that means that this particular web service or the Uh program that provides the website is not running this particular service is not on so let's switch it on And see if it works So we have switched this on and we'll go back to this was the pc that we were working with And let's go back to the web browser and try to open the webpage Dot 10 dot 10 Okay Yes, so now what we can see is the Institute site is opening from the pc So we have solved the first challenge. So what we did we first try to confirm the connectivity. So instead of checking the physical connectivity directly So we wanted to check the physical connectivity, but a shortcut to do that is Check it via ping. So if the ping works, you know that the physical then the network And transport layers are working fine. The error was on the application layer So on the application layer, we checked the web server and the service was off So we have successfully Started the web server. So now what we can do is we can go back and Look at what is the next challenge that we have