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Hey guys and welcome back. So in the previous nugget we had talked about the ARP table and

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the way we could retrieve this information was using the ARP command. Now what I want

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to talk to you about is the root command. Now again this is another deprecated command

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that we are dealing with but it just so happens that the LPEG2 examination does require we

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do have familiarity with these old commands and tools. So we must charge on and learn

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how to use it. So that is exactly what we're going to do. Okay so before we actually look

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at this command a very brief word on the concept of rooting. So in the previous nugget we actually

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talked about how devices actually communicate when they are within the same local network. So

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the way we communicate over a local network, devices ultimately talk to other devices using

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that MAC address hence why we were relying on the address resolution protocol so that we could

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actually ascertain and bind the MAC address information to particular IP address information.

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Now what we're going to talk about now is connections between remote networks. This means

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connecting to networks that are not the network that you happen to be on. So that would mean

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that if you are here, this could be your little computer and you want to speak to the big bad

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internet. Well the internet is a collection of many different networks and these are remote

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networks. You will be aware that the way you connect to the internet is via a device known as a

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router or if you are in America a router and quite simply all this device does is that it holds

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information about different networks in something called a rooting table. So if a packet is destined

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for a remote network, you send it to the router and the router will look it up in its rooting

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table and it will know which interface to send that packet out. Now we also have a concept of a

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default gateway. Now all a default gateway is, it is a router i.e. a device that is capable of

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reaching remote networks and you set that as your default next hop when you're trying to reach a

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remote network. Simply put your local machine, if it does not have rooting capabilities the way an

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actual router can, you're not able to reach remote networks but you can reach the router that is on

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and present within your local network. That will be the default place you send that traffic to. So

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whenever you have a remote destination that you're trying to reach, you don't worry about how to get

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there, you just by default send that information to your local router and the router will calculate

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the correct path and how to get that traffic to that destination. So like I say integral to this

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process is the concept of a rooting table. Now we also have our own form of a rooting table within

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our local Linux machine but it's much much simpler than what you would see on a typical enterprise

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router that we're talking about. Instead it's just going to have information relating to things like

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our gateway and the way we can actually display our rooting table on our little Linux machine is we

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can use this root command. Similarly we can also make modifications to the rooting table via the

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very same command using particular options and switches. So we can just say root and this is

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the information we get right here. What this is saying is that if we do not have another root

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specified for a particular packet, the default is to send it simply to the gateway. Now what about

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this one right here? For example here we can see if we have a packet that is destined for 192.168.0.0

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with a slash 24 mask. What do we do with it? Well it says here we're sending it to 0.0.0.0.0. Now when

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we see this in the rooting table what it actually means is that we should just broadcast this

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communication over the local network which indeed does make sense. Now notice we also get the

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interface related information. If we want to happen to make a manual change to the rooting

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table then we can do this by using the root command followed by the option add to add a root to the

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rooting table or we can say the word del to delete an entry in the rooting table. So let's say I

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wanted to manually add a new root. What I could say is sudo root add and I could specify the

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network I want to add. I will say dash net and the network will be 192.168. Let's just say maybe

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50.0 with a net mask of slash 24 so that's 255.255.255.0 and now what I want to do is to specify the

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default gateway so I'll say GW and the gateway would have to be on our local network so I'll say

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192.168.0. something and I will have that as 0.1. So if I hit enter type in my password and I say

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root now notice that I actually have manually added this entry here if we want to go to this

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network then we send it to 192.168.0.1 which happens to be my default gateway which we can

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actually ping right now 192.168.0.1 that is just simply my home router. Now if we want to remove

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this entry from the rooting table what I could say is sudo root del net and I'll say 192.168.50

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and again the same syntax net mask and the gateways 192.168.0.1 if I hit enter and I now say root

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that information of that entry should I say has now been updated and removed so really if you

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happen to be having issues connecting to remote networks you could use the root command see that

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you do have a default gateway configured and if you want to statically modify the rooting table

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to add your own entries as you so wish or remove entries which you believe may be causing you

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issues then by using the very same root command you can update the rooting table by either adding

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or removing networks or adding or removing gateways as you need but like I say the root

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command is indeed deprecated it is not the recommended way to perform such an action anymore

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it really is just there for legacy purposes for the examination there is a newer command on the

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block which has replaced the ifconfig command as well as the root command and others and that is the

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ip command and it's that command that we're going to be looking at next so I hope this has been

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informative for you and I'd like to thank you for viewing