Hi my name is you have from each Epix welcome you all to Cisco firewalls course today in this video
we will cover the topic of the basic a as a configuration by the end of this video you will be able
to understand how we can get a is a firewall up to work and what are the basic configurations to be
configured on the Cisco firewall.
So let's start as we can see in the figure we have here a Cisco firewall is a we have an inside network
which is actually has a inside router and an outside network whatever what's the outside network is
it can be internet it can be a remote office whatever the important here.
The important thing is there is a router here.
OK.
So the firewall connects the inside with the outside.
All right as we discussed in a previous video we have what we call a security level for each interface
which is by default one hundreds for the inside and zero for the outside.
So in this little example here we will see how we will assign an IP address to each interfere.
Interface and how we will actually assign also a security level for this interface and how to make it
up to work by the way.
Just this morning not here when you see a green sign here it means the interface is up on working took
a thread.
It means it's down.
So let's see this little example here.
We will configure here.
This interface gigabit interface 0 over 0.
So first of all as probably most of us know we have to first enter the global configuration mode so
configure terminal then prompted a change from this side to the conflict sign then we enter that interface
configuration mode which is gigabit 0 0.
So we type interface Gigabit Ethernet zero over zero.
Now we will give it a name since this interface will be the outside interface.
So we will use this command name if I F stands for interface the short for interface or name interface
space outside which is this one.
So we give it a name here.
We told the firewall.
This interface gigabit zero over zero.
That's your outside interface.
All right press enter.
Second step is to assign a security level for this interface which is by default 0.
But we still need to reconfirm this.
So we type security that's Level 0
then is this interface going to work now.
Of course not.
You have to assign an IP address to it which is this one so IP address you assigned that IP address
which is this one the subnet mask here is twenty nine which is equivalent to 2 5 5 5 5 2 5 5 2 to 48
and then the last step is then no shutdown command because all interfaces by default are shut down.
So we need to turn them on no shutdown.
OK.
That's it.
The interface is going to work and past traffic between the firewall and the outside throughout it.
Of course on the other side on the other side though which is that outside router we have to configure
this interface as well.
So both sides will communicate.
OK Justice Moore not here I included in this slide if you will connect to the firewall through a console
port it will prompt you for a password but you just can press enter.
There is no console password by default and also it will prompt you for the enabled password that enable
is there step before the step the prompt for the enable mode is just different from this so it will
prompt you for an enabled password but you just press enter because there is no enable password by default.
Ok so configure terminal enter the interface configuration mode give it a name give it a security level
give it an IP address then the last thing is no shut down
let's see another example here here our firewall actually is connected to three interfaces apart from
the inside and outside there is an interface called DMZ which is that demilitarized zone a zone that
you can actually place any servers that you are worried too like anybody can attack them like your internet
web server or internal DNS server you can place him in a zone called DMZ or demilitarized zone you can
give it a name by the way we're just here for this example we use DMZ OK so we have free interfaces
here the outside which has the security level of 0 by default the inside which has security level hundred
one hundred by default and the third interface here which is the DMC we will give it the security level
of 50 OK.
All right.
And as I mentioned before you can change.
Change those numbers you don't have to stick with those default numbers you can give it instead of 50
30 instead of 100 you'll give it 90 it's up to you all right.
So let's see what are the configurations here.
First interface gigabit.
1 over 1 which is this one the outside you can give it also a description so the description here we
give it connection to the Internet.
It's not a necessary step.
It's actually an optional step.
But we give it here.
Description name interface outsides.
As we mentioned in the previous slide security level 0 IP address which is this one tenth of 1 to 1
to 1 backslash 24 which is 2 5 5 5 5 2 5 5 0.
Then no shut down.
You can just type no shut you're going to have to type the full command no shut down Cisco firewall
will understand you're just type no shut and the firewall under will understand that you mean no shutdown.
OK.
Second interface is the gigabit one over to which is this one the inside.
Same thing description to land or connection to land whatever you can type whatever you want to.
The description here to learn means connection to the land name interface inside security level one
hundred IP address this one 1 9 2 1 6 8 0 0 the 1 backslash twenty four OK third interface which is
that DMC the same steps for each interface one over three description to DMC 1 which is this zone this
interface name interface DMC 1 we give it just the name security level 50 and last thing is the IP address
which is 1 9 2 1 6 8 1 vote 1 backslash 24 and not shadow so is the same configuration for every interface
you just assign a different IP address and different name and of course a different security level.
OK that's all for this video in the next video we will cover a topic of a Cisco packet tracer which
is actually a free network simulator from Cisco and we will see how you can use it to practice your
Cisco firewalls configuration thank you very much for watching and see you in the next video.