Hi my name is you have from teach ethics.
Welcome you all to Cisco firewalls course.
In this video we will cover some features of the Cisco is a firewalls and the main services that Cisco
is a firewalls provide by the end of this video.
You will be able to understand how Cisco firewalls operate and what are the services they can go right.
So let's start as we mentioned earlier as a brief Cisco firewalls it is a day for what we call as teeth
full packet filtering which is actually an access control list and access control list.
ACL is the short for access control list.
They filter traffic based on drools.
You configure yourself cell phone on the AC appliance.
The rules actually dictate whether to allow or deny traffic by the way.
We will cover access control list in a separate video as a lap.
OK.
The second feature or service that is a firewalls provide is the application inspection
from the name out as the name implies.
Application means Layer 7 which is the application layer.
So they as a firewall can listen to conversations between devices on one side and devices on the other
side.
So if we have here our internal network and the outside network which is the Internet the Cisco firewall
here is a in between.
It listens to conversations between the inside and outside on Layer 7 which means protocols like HDTV
or FTB next.
It is a firehose can provide net services which is the network address translation embrace net that
means translating the private IP addresses in the internal network to public IP addresses to be used
on the internet because you can use private IP addresses on the Internet.
So they have to be translate okay.
Also we will cover that in a separate with you as a lab.
Next service is that the LCP which is the dynamic Host Configuration Protocol that is a can provide
internal clients or interim hosts with IP addresses automatically instead of just assigning static IP
as so many the pure form exactly like a router here.
So the AC here is like around not is said was that that Delta provides the AC can provide it also that
it should be service can be provided by the AC the last service here is routing the AC complete for
routing exactly like our outer does and it actually supports all or most of the known routing protocols
like crap e.g. R.P. or SPF even aesthetic crowding can be configured on the AC firewall so they provide
all the services that a regular router can provide OK.
And as I mentioned we would have a separate lab in future video on configuring access control list on
BSE.
Let's move to the next line.
Here you go how inspection fire or inspection packets as a state full works how a state wide inspection
works as we mentioned earlier as a brief hit is the firewall.
The inspection firewall it maintains a table of the connection.
These are the information recorded by the firewall regarding any connection between the inside and outside
the main information included in this table which we call a state table are the protocol used source
IP address destination ip address source and destination port and also the connection tracking state
which is as shown here either established it can show as OK but in Cisco firewalls this status shows
as established.
Here is the port number destination IP address.
Source port.
Destination Port and the source IP at so states for inspection firewalls were actually on these layers
for from the transport and below OK.
They don't go further through the application layer as the application and inspection firewalls do they
stop he'd add the transport any OK let's move forward.
So what are the advantages of the state's full packet inspection as we said.
They maintain records of all connections in a state's full table or state table.
Here is that this advantage as the previous slide mentions the stop at actually Layer 3 and sometimes
they go to the transport layer but they don't go further to the application layer.
So some actually risks cannot be identified so they can't identify or prevent any application layer
attack.
And this is the main disadvantage how we resolve this.
Simply we use an application and inspection firewall which goes further to layer 7 of the holes I model
so they can perform deeper inspection to see any secondary or hidden channels that are about to be initiated.
All right so you might ask me so why should I buy a state's full packet filtering firewall.
Why I have the chance to buy an application inspection firewall.
Here is the answer if you don't have to worry about this all more than firewalls including Cisco they
have all in one inspection services so they have packets filtering state for filtering and application
inspection capabilities in a single device.
So it's all in one solution or more than firewalls like this.
Okay so that's all for today's video.
In the next video we will cover the topic of what we call interface security levels for the Cisco firewalls
thank you very much for watching and see you in the next video.