HI MY NAME IS SHE HAVE FROM teach Epix.
Welcome you all to Cisco firewalls course.
In this video we will cover some configuration of Cisco as a as a Net server by the end of this video.
You will be able to understand how we can configure the firewall from Cisco to act as a Net Server or
an attractive.
So let's start
all right.
As we discussed in a previous video Nat is a network address translation which translates the private
address to a public outside address.
To be able to communicate on the Internet and on the outside world.
All right.
And this figure as we see here is the Cisco is a firewall acting as a natural leader or a Net Server.
It doesn't matter the name is the same meaning actually net operates in both directions.
So from inside to outside and vice versa from the outside to the inside.
And why is that.
Because if you are an Internet user here and you want to communicate on the Internet you will need a
public address.
So that is the inside to the outside translation.
But if you are an outside user and you want to access the Internet network you need to translate your
public IP to a private IP.
So that's where the outside to the inside.
Translation OK.
So it's both ways inside the outside and outside the inside.
OK.
So let's move to the next slide here.
What are the comments you need to configure.
Nothing.
And we will discuss here specifically the static net.
All right.
The configuration steps are very easy actually only three steps in order to configure a static mapping
which is actually fixing that thing.
One private IP translates to one public IP as simple as that.
So here are the steps.
First of all we need to make at least one interface as outside which is this one.
And one interface inside.
Which means we need to name the interface as we discussed in the previous we do one inside and one outside.
In order for the firewall to understand who is inside and who's outside and of course we have to give
each interface an IP and also give a security level which is from zero to 100.
We will see this practically in our lab later.
All right.
Second command the use is called Object network mainly the object network is a command to define the
object on your topology that you want to apply the Nats rule for example.
This internal P.C. is considered an object.
So if I want this internal P.C. to communicate with the outside world I need to configure a natural
or a static natural specifically for this computer.
So this computer or this Internet C is called an object in Cisco terminology.
So we need to define what is the object we need to apply the Nats rule on.
All right.
Here are some guidelines for using the object network command.
First of all you can use this command in both single mode and multiple context mode.
As we discussed earlier there is a single and multiple context mode.
So this command works on both modes.
Second what is the what is the final mode.
Also it can operate and work in grounded and transparent firewall mode.
We discussed that firewall modes in an idiot video as well.
So this command works on both routing and transparent trout it is the layer 3 firewall the firewall
is considered as our outer layer 3 and the transparent is Layer 2 appliance which means the AC acts
as a switch.
All right.
Also this command does not support IP six only IP before.
OK.
The last guideline here is you can apply or defined only a single net rule for a given object.
So if we have these objects which is the internet that b c we can apply only one natural on it.
OK.
If you want to apply many rules you would need to create many objects.
So every object will have one single natural.
Let's see here how the command looks like first of all you enter the global configuration mode which
is configured terminal then the prompts change to this one config.
Here you go.
Here is a command object space network and then you define the object that you need to apply the natural
law which is the inside dash.
This one line you give an IP address for this inside.
P.S. You see how the prompt here changed from configured to configure network object you use the command
host and you'll give it an IP address which is here in this trigger and the two the three the two as
simple as that you defined the object you give it an IP address that's it and the third command actually
is called met inside outside or not outside inside which actually defines the not that action whether
you want to translate from the inside to the outside or the other direction.
All right.
So here are the three configuration commands OK before we discuss this conflagration example let's go
to Cisco packet tracer and see how we will configure our next lap.
Here we go we open packet tracer Cisco packet tracer.
We go to the firewall tab here in Cisco packet tracer.
We have only two firewall modules 5 5 0 5 5 5 0 6 what is the difference.
Let's see what is the difference.
Let's grab both of them.
If you point the cursor on the 5 5 0 5 you will see the interfaces are all ethernet interfaces plus
two V lan interfaces the V Line one by default takes the IP address of 1 9 2 and 6 8 1 to 1 and the
default hostname is Cisco is a.
Of course you can change this right.
However if you come on 5 5 or 6 you will see that the interfaces actually are 8 gigabit ethernet interfaces
plus management interface which is the management one one over one.
All right.
So it depends on your topology.
What do you want to do.
You choose either one of them.
Right.
And as you can see here the Gigabit Ethernet one over 16 the IP 1 9 2 1 6 8 1 the one here the V lan
one interface takes that 1 9 2 1 6 8 1 to 1 and this is the default configuration for the Cisco firewall
and you kind of change it of course OK so what can we understand from this.
We can understand that this firewall 5 5 0 5 is considered a transparent firewall by default which means
it operates on layer 2 because it uses the land Villanova v lands operates on layer 2 and the 5 5 or
6 is considered routed in routing mode by default and it has a management interface which doesn't exist
on this one.
All right.
So let's go back to our slide here.
Here is that topology that we want to configure as a in between inside b c and outside B C or whatever
you want.
You can change this icon to a server to a cloud.
It's up to you.
So let's see here.
We will use here the 5 five or six.
So let's delete this one in order to delete go to this on this delete that and just click on the item
that you want to do.
All right.
If you want to select an item just go to the select.
Here is if you want to resize it.
And here this tab is for placing notes if I want to place a note here or whatever I want I can type.
OK.
All right.
So we grabbed one firewall here.
You can of course move it.
Just click on it and move it by your left mouse button here.
We will grab one P.C. sign on the finger and one browser
let's take this routing down nineteen forty one and we also grab what we see here which will be the
Internet B
OK we connect them as soon here in the figure B.C. fired or and another P.C. as I said it doesn't matter
what's how it looks like it can be a P.C. it can be a relative as long as it has an IP address it doesn't
matter how it looks like.
All right
so let's connect those.
We will see the detailed configuration in the next video take one a straightforward game here connect
it to the network card of the computer and then to this one gigabit Ethernet one over one and then again
take one cable from here.
By the way this is the detailed lab that we will configure later.
Ok the one connection here connected to gigabit Ethernet one over two and then to the gigabit internet
on the router of course where we need to give IP addresses for those set for those interfaces in order
to become green color.
OK.
Let's discuss here.
Quickly the configuration.
What is the purpose in this.
In this example we need to allow the host heat of the internal host which has the IP at this standard
one to the 27 to communicate with a remote P.C. which has this IP address which is a public IP address.
OK.
So we need to apply the steps that we discussed in the previous slide
that translation would be like this from this inside IP address to a public IP address which is this
one we will discuss this in the next video using packet tracer.
Thank you very much for watching and see you in the next video.