Hi my name is she has from teach ethics.
Welcome me all to Cisco firewalls.
Course in this video we will cover the topic of Cisco as a interface security levels by the end of this
video.
You will be able to understand what you mean by Cisco INTERFACE security level and why we need this
in our network and in our configuration.
So let's start Cisco INTERFACE security literally means you assign a number to each interface connected
to the is a firewall.
The number is between zero and one hundred.
Why we need to assign a number to an interface mainly because Cisco actually manufacture this feature
or provided this feature.
If we have for example two interfaces here one inside and one is outside connected to the outside world
by default without to touch that configuration without you change anything in it by default the outside
is assigned a limit of zero and the inside is assigned the number 100 which is the maximum OK.
So here you go.
Let's move to the left side Steger here.
Here we have an inside interface connected to LAN or a P.C. in a local network.
And he does the outside interface with a security live in zero connected to another p.c. in our remote
network which means it's an outside network.
So Cisco actually
says when you pass traffic from the lower to the higher security level it's by default denied.
Which means if you have here the outside security level of zero and the inside is hundred.
So zero of course is lower than 100.
So the traffic is by default denied.
And of course why why default denied because traffic is passing from an untrusted zone to a trusted
zone which is your local network.
On the other side from a higher to a lower security level the traffic by default is allowed OK.
Of course you can change this manually but this is the default configuration.
So traffic allowed to pass from higher to lower level by default traffic is denied from the lower to
the higher.
By default OK so remember the bigger the number the more trust you have in the network.
So this number actually the number that you assign which is between zero and 100 defines the trustworthiness
of the network that the interface is connected to.
By the way you don't have to stick with the one.
You can change it to 50 or any number you want as long as it's bigger or higher than zero.
Also the number zero you can change it it's up to you to change any number.
And by the way if we have a third interface here connected to the Cisco firewall you can assign it a
different number like 50 40 it's up to you so if we have for example a third interface here and we assign
it the number 50.
So that means if traffic is passing from the outside to the zero level to this interface which is 50
it will be denied because it's from lower which is 0 to the higher which is 50 OK we will have actually
a lab later in each individual I will show you how to assign a security level to an interface
in the next video we will discuss how to access the Cisco is a firewall configurations and what are
the different methods of accessing that configuration.
That's all for today's with you.
Thank you for watching and see you in the next video.