Hello.
My name is she had from Teach Epix.
We welcome you all to Cisco firewalls course in this video we will cover introduction to firewalls technologies
and services which is part of Cisco firewalls.
Course by the end of this video you will be able to understand the main concepts of firewalls and why
we need a firewall in our network.
So let's start our presentation here
as we may all hurt a firewall is considered a security device that monitors incoming and outgoing network
traffic and decides to either allow or block specific traffic.
And this is of course based on a defined set of rules firewalls has been has been used for the past
25 years as a security solution and a firewall can be either a hardware or software or even both
as we can see here in this figure.
This is a firewall here.
This is our internal network and this is the outside world which is mainly the internet so the firewall
here represents a barrier between your Insight Network and the outside world
so why do we need the firewalls
as we can see in this figure we have here our inside which we consider a trusted network and the outside
world which we consider untrusted because we don't know what's coming from there.
So here is the firewall between our trusted and the untrusted outside world which is mainly the Internet
so we can see the purpose of the firewall is to control what traffic is allowed to pass from one side
to another either from the outside to the inside or even from the inside to the outside
a firewall come block traffic intended for a particular IP address or server ports which means if I
have here my internal network and I have specific requirements in my company that outside users cannot
access some or all of the internal servers for example the internal Web server or the Internal DNS server.
So I can configure a firewall rule here to block traffic from the outside to the inside.
Of course every company has its own technical requirements so mainly we can see any firewall as a general
rule has two network interfaces or two connection sites one
interface is connected to the outside world which is the external side and the other side is connected
to the inside network or your local LAN
in our next video.
We will cover the general firewall characteristics.
I hope you enjoy the video.
Thank you very much for watching.