Overview
Although the course content does not say anything about configuration for this section, just verification, I guess it is assumed that you would know that since you use the computer on daily basis, the least you could do is to know how to setup your IP address right? I have included configuration for IP addresses on the various Operating systems.
Hosts communicate with each other on same and different subnet from time to time. For this communication to be successful, every host needs to have some IP parameters/settings to work correctly. Some of the parameters includes;
- The Host information (Each host must have its own IP and subnet mask)
- The Default gateway /Router information (The host must know the default gateway IP which must be on same subnet)
- The DNS information (The host must know the DNS info of one more DNS server)
The Host must have the correct IP address in the same subnet with its default gateway or router. example 192.168.10.10/24.
The Host must also know the default gateway IP which in this example will be 192.168.1.1 /24 and must also know one or more DNS server IP where the name resolution requests are sent to. Some companies have separate servers for the default gateway and the DNS while some other use same server. Whatever approach, the important information to capture is the DNS server IP information.
How to Configure the IP parameters
There are a couple of ways to configure your IP address on your pc. You could (1) right click the network icon on the lower right side and click “Open Network and internet settings”, select your Ethernet and select Change adapter settings, select the adapter type and double click and select properties, select TCP /IPV4 and select properties again, select “Use the following IP address”, then specify the ip address, subnet mask, default gateway information and save. (2) You could also go through the control panel, under Network and Internet, click view network status & Tasks, OR Click Network and Internet directly and click view network status & Tasks, Change Adapter setting which takes you to the network adapters installed on the pc. You can actually change the name of the network adapter to something more easily understandable by you by just pressing F2 key and you are allowed to change the adapter name.
You can either double click the adapter name or right click and go to properties, then, look for (TCP/IPV4) in the list and click properties again, then, click “Use the following IP address”, specify your IP address, subnet mask and the gateway information and this is called Static IP address assignment. The option for “Obtain an IP address automatically” will be discussed under DHCP section.
How to verify the IP parameters
In windows environment, you can use either the GUI (graphical user interface) or the command line. For me, the command line is faster. For the GUI, its the same process like configuring an IP and there you see all the details of the IP address of the pc =Start button -> Setting-> network and Internet -> View Hardware and connection properties
For Command line, you will use ipconfig OR ipconfig/all. The ipconfig/all apart from showing the ip address details for the host, it also shows the DNS setting information too while the ipconfig shows you the base configuration.
Once you verify your configurations, you can always test by pinging.
Other tools in verifying and troubleshooting in windows
Ping – ping 192.168.1.1 (Pinging your default gateway -whatever the IP address is is a good way to begin testing if you can’t get out of your network) and ping 192.168.1.1 -t (this pings forever until you stop it with Ctrl +C)
tracert – This is the windows version of trace route. This helps you see all the routers along the path of your destination. Example: tracert -d 8.8.8.8 (the -d stops the action from trying to resolve hostnames, trying to do a reverse DNS lookup for the ip addresses, which most of the times fails so including the -d makes it faster to trace the path, 8.8.8.8 this is googles DNS server).
nslookup- This is used for testing DNS services when your connection to the internet is down and when you type a domain name and it returns the IP address, it shows the DNS server is okay. nslookup, then type the domain name, if it returns the IP, you are good, then you can exit the nslookup utility.
netstat -r: This command list the host ip routing table. Here you see the info like the metric, gateway On-link which means, the PC thinks the destination is on the local subnet
Like windows, Mac also has GUI for configuring and verifying Host IP settings and other network commands. The Host IP settings can be found in the Network section in system preferences as demonstrated in the video. Mac and Linux OS support the “ifconfig command” to list information that are similar to what you will see on windows “ipconfig/all” command. However, the ifconfig command does not have the (/all) like ipconfig/all has and does not also list the default gateway or the DNS servers.
You can also use the Ping command to test and in mac, it’s a continuous ping and to stop, you have to press ctrl+ c unlike in windows where a continuous ping will require a (-t). nslookup is another good tool to know just like the way it is operated in windows, it tells you the DNS server is working fine. To get the default gateway and DNS information, you will have to use 2 other different commands; netstat -rn
The GUI to display network setting in Linux differs compared to Windows and MAC and this is attributed to these two main reasons; (1.) the Linux world has a large number of DIFFERENT Linux versions or distributions. (2.) Linux separate the OS from the GUI, so that a user of one Linux distribution can choose between different desktop interfaces and as a result of this, you will see different GUI screens to display the network settings.
Taking a look at the MATE desktop, which is included in the Ubuntu Mate Linux distribution (www.ubuntu-mate.org).
This shows the details of a wireless LAN and includes the IP v4 address, mask default router and primary DNS IP address. However, from the command line, Linux host will often support a large set of commands called net-tools. This library include ifconfig and netstat -rn (like in Mac OS) which has since been depreciated and replaced “ip route” library which includes a set of replacement commands and functions performed with the IP commands .