HI MY NAME IS SHE HAVE FROM teach ethics.
Welcome you all to Cisco firewalls course.
In this video we will cover a lab conflagration which allows an access from the outside to the inside
zone Using Cisco as a firewall.
Access Control List right by the end of this video.
You will be able to understand how to configure that is a to allow communication and session initiation
from the outside to the inside which is actually denied by default.
So let's start as we discussed in a previous video by default communication from the outside to the
inside is denied.
Why.
Because the security level for the outside network is by default 0 and the security level for the inside
is by default 100.
So from the outside to the inside by default communication is denied.
So what we need to do in this video we will need to configure this firewall to allow communication between
DBC which resides on the outside zone to this P.C. which resides on the inside zone.
We will need first to configure the interfaces.
This is the inside.
It is outside.
We need to configure a security level of 90 instead of 100 and a security level of 10 instead of 0 for
the inside.
All right.
And then we will create an access control list to allow communication from the outside to the inside.
So let's start
let's open Cisco Packet Tracer.
We will grab a Cisco firewall here five five or six.
We will grab two pieces
one here who will be for inside and one for the outside let's connect both of them.
Good again.
Here you go let's give an IP addresses for those species.
We will give this 1 1 9 2 1 6 8 1 to 10 and this 1 1 9 2 1 6 8 1 20 as she was here in disfigure okay
configuration tab
1 9 2 1 6 8 1 or 10 the default subnet mask and also we will define the gateway for this P.C. the IP
address of the Internet interface of the or the inside interface which is by default 1 9 2 1 6 8 1 1
and that's it
for the other P C same thing
we will give it an IP address of 1 9 2 2 1 6 8 1 20 the default subnet mask and
the gateway here will be will give us a different IP address which is the IP address of this interface
the outside which will be 1 9 2 1 6 8 1 dot 2.
Okay
so 1 line 2 the 1 6 8 0 1 2 2.
That said that's all we need for those two pieces on the firewall Gigabit Ethernet one over 1 is configured
already we need now to configure the Gigabit Ethernet one over two but let's first give a name for that
Gigabit Ethernet one over one as an inside so enable entered
configure sturdiness
interface G I one over one
it has the IP address already so no need to provide to an IP address we will just name it inside.
So name interface name if
inside
just in case it's not up we will issue a no shut down.
But before this we will need to assign a security level of 90 at the chores here.
In this figure so a security level SDC 90 no shut down.
That's it type exit.
Then now we will configure Gigabit Ethernet one over two.
So interface G I.
One over two.
Let's give it an IP address of 1 9 2 1 6 8 1 2.
So IP address 1 9 to the 26 and between the two.
We need to provide the subnet mask which is 24.
So 2 5 5 2 5 5 2 2 5 5 0.
We will give it a security level of 10 as it shows year so security level 10 and we would name it an
outside interface.
So name if
outside
now let's exits from this interface configuration mode to check if the configuration have applied.
So controls it
and lets type show IP address show IP address.
Here you go.
1 over one has this IP address which is the inside one over to the outside and has the IP address
and the same thing will will show if we type show running configuration show run it will appear here
as you see security live in here of 90 for the inside and here is then for the outside.
And these are the IP addresses for both interfaces.
OK
type controls set to go back to that enabled mode or the privilege mode.
Now
since the default behavior of the firewall is denying communication from the outside to the inside.
So now we will need to create a fort an access control list on this firewall to allow communication
from the outside to the inside.
So that session direction or deficient initiation would be in this direction.
OK.
So let's create the firewall the access control list in the firewall.
So type configuring config map terminal config.
T
Right access this list.
Type question mark we will give it a name.
Here it tells you to choose a word.
We will give it a name of out underscore in so out
underscore in this is the name of the access list again type question mark.
It would prompt you.
Is this an extended access list or deny or permit.
This would be an extended access list so we would type extended or E X T and step again question mark
it will prompt you either you want to deny or permit.
Of course we want to permit that communication from the outside to the inside.
So type permit
sorry it doesn't matter if you type it in uppercase or lowercase.
There is no difference.
Vermouth again question mark.
What do we need to do here.
We need to allow IP communication
from any host.
Which means anywhere.
To this IP address.
So here are the options when you type question mark it gives you it gives you these options.
So we will choose IP
that question mark again.
What do we need to do we need to allow communication from anywhere anywhere means from the outside world
from the internet from anywhere to this P.C. so type any.
I get calls from Mark all right what do I need to do now.
It gives you this option when you type question mark from any to any or from any to a specific IP address
or from any to a host or from any to an object.
Actually we need to choose the host because this is a specific host.
Host means a computer.
OK so we choose host type hosts again question mark now.
You need to define the IP address of this host which is 1 9 2 1 6 8 1 the 10 and that's it you're done
press enter the access list is created
okay.
As I mentioned before the access list is useless until you apply it on a specific interface.
So we need to use the command access group.
So access Nash group question mark
it prompts you to provide a word or the name of this access list.
The name of this access list is out underscore in you have to type exactly the same name.
So if it's an uppercase you type it uppercase it's lowercase type lowercase exactly the same.
So out underscored in if you do remember what to type.
Just use question mark how do I want to
list type in in in
so how do I want to apply this access control list.
I want to apply it either inbound or outbound.
Of course I want to apply it inbound on a specific interface inbound on these outside interface inbound
means that traffic entering going to this outbound or outside interface so type in this type it in lowercase
in question mark again.
You need now to define the interface that this access control to be applied on.
So type the word interface question mark again.
It prompts you either choose inside or outside.
This interface which is this one that has that the IP address of 1 9 2 1 6 8 1 2 is actually the outside
interface.
So we will choose out side.
That's it you're done.
You apply.
Now the access control list on the outside interface for the inbound traffic press Enter press control
Z to go out from this global configuration mode so control that.
Now let's check and verify the configuration for the access list that we created.
So we will buy sure access specialist show by the way.
If you don't know again what to type just type show.
Question mark.
It will show you all the available options to show.
So here is an option to show the access list.
The one on the top okay.
So show access.
That's list enter.
Here you go.
It shows you the access list that you created the access list.
Name is out in
took extended access list.
Pyramid IP protocol from any any means.
This is the source address.
Host this one which is the destination atlas.
So this is the access list that we could eat.
Okay.
It shows you everything name.
It only has one line or one to statement.
So line 1 the type of the access control list is extended.
This is the rule to apply pyramid.
This is the protocol to use which is IP.
This is the source and this is the destination.
Also you can type sure running a configuration to see all configuration on the firewall.
So she'll just type Ron and press step it will complete the commands for you.
Okay.
It shows you everything here.
The interface configuration.
Just press enter to go down when you see more.
Just press enter to go down enter enter enter enter.
Here you go
it shows you the access list that you actually configured
and it shows you also.
How these access control list will be applied when which interface which is outside.
What is the direction of applying this.
Access Control List.
Inbound so that's all for this video.
Thank you very much for watching.
And this is the end of this curriculum.
Thank you very much again for watching and see you in Nick's videos.