CMP2007M – Networks and Network Systems Workshop 1
Introduction – Network Tools
Welcome to CMP2007M – Networks and Network Systems workshops. In this workshop we are going to make sure that you are all up to speed with the available built in tools that come with the operating systems we use.
In this workshop we are going to look at introducing some basic networking tools, some of which are provided by default in Windows. These tool will allow us to better understand the processes by which networks operate.
The first of these commands will be used through a command window interface:
Click: Start –> Run –> type ‘cmd’ and press enter (press WindowsKey-R for shortcut)
You should get:
Tool 1 – IPConfig
ipconfig is a tool that many of you may be familiar with which gives us information about the computers communication interfaces. There are several ways in which we can use ipconfig:
1) Type ipconfig and press enter this will give you basic information about the network interface on the computer
Don’t worry about most of this information for now, we are just concerned with the IPv4 address. This tells us that this machine has an ‘address’ on its Ethernet Adapter of ‘192.168.0.2’.
CMP2007M – Networks and Network Systems Workshop 1
2) type ipconfig /all this will tell you a LOT more information about the computer’s network, take a moment to have a look through this and see what is there. In particular, pay attention to the linecalled‘Physical Address’.
Time for a joke….
Here is how system administrators play jokes on their colleagues….
3) Type ipconfig /? and you will be given a list of comments you can try. Have a go using: ipconfig /release
ipconfig /renew
and see what these do! 🙂
CMP2007M – Networks and Network Systems Workshop 1
Tool 2 – Ping
ping is another tool that allows us to investigate the network and settings. ping is used to send requests to another machine (anywhere in the world) and is a very important diagnostic tool. It allows us not only to know if a machine is viewable on the network and is reachable, it also tells us how long it takes to ping the machine, that is, its response time.
Testing
Working with the person next to you, I want you to ping their machine. In order to do this you use the command in the following way (have a look at ping /?):
C:\Users\Keukpa>ping [ipaddress]
where [ipaddress] is the address of the computer you wish to ping.
C:\Users\Keukpa>ping 192.168.0.1
Pinging 192.168.0.1 with 32 bytes of data:
Reply from 192.168.0.1: bytes=32 time<1ms TTL=64
Ping statistics for 192.168.0.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 36ms, Average = 9ms
C:\Users\Keukpa>
Note: By default, windows prevents ping being used [I’ll talk about this in the coming lectures], therefore you will need to enable is. See Note 1 at the end of this worksheet on how to enable Ping.
This sends 32 bytes of data to the destination machine and gives you a response time. I want you to both ping each other’s machines and see if the response time differs. Next, try pinging someone else in the room and see what response you get.
You can also ping by domain name, such as www.lincoln.ac.uk
Try pinging the following:
www.lincoln.ac.uk
www.blackboard.lincoln.ac.uk
www.google.co.uk
www.jcmurray.com
You’ll notice it gives you the IP Address of the domains. Do you notice anything about the response times? Speak to a demonstrator about this.
TTL
You will see at the end of your ping request response that is a TTL number, this varies depending on machine and destination. Try to work out by pinging various different destinations what you think this number might represent.
CMP2007M – Networks and Network Systems Workshop 1
Tool 3 – Trace Route
Windows comes with another very good tool, this is called tracert. This tool tells us the route our
data takes as it goes from our own local machine to the destination. It is used in the following way:
C:\Users\Keukpa>tracert [IPAddress]
Enter the [IPAddress] of the machine next to you. You will get something like the following:
C:\Users\Keukpa>tracert 192.168.0.106
Tracing route to 3dprinter-PC [192.168.0.106] over a maximum of 30 hops:
1 <1 ms <1 ms <1 ms 3dprinter-PC [192.168.0.106] Trace complete.
C:\Users\Keukpa>
This is because you are on the same switch network as these machines, and as such directly connected. Now try replacing this IPAddress with the IP Addresses of the domain names I gave you previously. What do you see?
You should see that you go through a LOT of hops, and each one takes longer and longer as we go….
Additional Task
Try to tracert to the following IPAddress: 82.7.137.59 See if you can find the following:
Where this machine is located (i.e. what town) What ‘type’ of machine is it?
What ISP hosts the network?
CMP2007M – Networks and Network Systems Workshop 1
Linux
You’ve seen only some of the tools that are available for network support on a Windows machine. There are many more that we’ll look at throughout the semester, however there are also tools available for another operating system.
Reboot the PC you are currently on and boot into Linux. Once in Linux, follow the worksheet again, but this time notice the additional and different information. For example, does the TTL value change?
In Linux, the commands you’ll need are:
ifconfig ping traceroute
Summary
You have been introduced to three very simple yet very useful tools available for network analysis. In coming weeks we will expand on these and use them to learn more about network structures and usage.
I will go through these tools in lectures in more detail.
Note 1: Enabling Ping on Windows 10
Here is a useful resource that will help you enable this:
End of Workshop