Good Evening To You All
From today, work will started getting much for you. That’s why u need to be more serious about this.
Don’t pile up your work.
Let’s begin
TOPICS IN CCNA
1. Fundamentals of IP address
2. Initial Configuration of Cisco router
3. Routing
4. Access control list
5. Password Recovery and ios/Configuration backup
6. WAN TECHNOLOGIES
7. Switching
8. IP Services
9. Intro to NAT
IP ADDRESS
IP ADDRESS is the numbers networking devices used in communicating with each other. This number is
managed by an ISP company called IANA.
IANA= Internet Assigned Numbers Authority.
IANA controls IP address globally.
Every continents have IANA branch offices where pools of IP address are kept for release to companies in
need of it.
In Nigeria we have ISP offices that sells IP address to companies. Example is the NIRA.
NIRA= NIGERIA INTERNET REGISTRATION ASSOCIATION.
If I wish to network two companies together, all I need is to get license from NIRA. This license is what
we technically called IP address. Yes, let’s take it like that for lay man understanding. Later we elaborate.
Let’s assume I hv gotten an IP address for my GTB router in Kogi and another IP for the GTB router in
Abuja. What will I do with it?
I hv to configure the addresses on my routers.
Remember, u will also hv to configure an IP address on ur switch and computers.
My focus for now is on the routers.
Your focused is to read the few pages manual on how to configure d computers to share files.
You will understand from the manual that IP address is of two types, the private and public IP address.
The private address is used to configure devices on our Local Area Network. The computers and switches
are devices on our Local Area Network.
The public IP address is the address we configure on the Wide Area Network devices.
The router above is an example of a Wide Area Network (WAN) Device.
Learn more about Types and Methods of Networking from the manual.
From the previous scenario, u will noticed I have 3 main shapes:
1. Circle, this represent the router in the organization
2. The rectangle, this represent the Switch
3. The triangles, they represent the computers.
You will agree with me that each of the devices have an IP address attached to it except the switches. Is
not an omission. Don’t worry yet.
For now I will be concerned about the router.
The router here have two points where cables are connected to and each point have an IP address.
E.g, the GTB router at Kogi State is having two IP addresses
There is one pointing to the switch which is 192.168.1.1
There is another one pointing to the outside network. That one is 11.0.0.1
The 192.168.1.1 is the LAN address of the router.
The 11.0.0.1 is the WAN IP of the router.
All this addresses must be configured on the router. I will show u how to do that.
To understand better, the 192.168.1.1 is a free IP address. You will generate it from pool of free IP address.
Such address is not purchased from ISP or NCC in Nigeria.
But the 11.0.0.1 is a public IP address and must be purchased before u can use it. Such a purchased IP
address is needed when u have a branch office that u want to have access or Communication with.
Take for instance, if there is no 11.0.0.1, it means the router can’t access the public network, meaning it
can’t communicate with outside network, meaning it can’t communicate with GTB Abuja.
Meaning money deposited in Kogi State won’t be received in Abuja.
Meaning football match played in Germany can’t be received in other countries like Nigeria.
Meaning, channel TV can’t broadcast to Other states .
Meaning, MTN line can’t make calls to other lines in other locations.
What I am saying is that , without public IP address, there is no far distance Communication. It means
there is no internet. It means Facebook and WhatsApp won’t exist.
That’s funny.
Thanks to public IP address
Zoom the lab, and u noticed I hv got 6 routers on that table.
3 routers on my left hand side, and 3 routers on my right hand side.
I hv got 4 switches.
Two switches on my left hand and two on my right.
Check well, each side contains 5 devices, seating on top of each other. The first two from below are
switches. The other 3 from above are not switches but routers.
Same goes to other side.
Let’s assume, the left hand side is GTB Kogi, and the right hand side is GTB Abuja.
At GTB Abuja , we got two small devices. The two devices are WAN devices. Without them there is no
WAN connection.
Only one of the router, yes the router at the top will be connected to the small device there called Cisco
Aironet and in turn, Aironet will be connected to Cisco Bridge
The Cisco Bridge will be connected to the satalite dish outside the office, with a cable called coaxial cable.
This cable is the same as the black cable that connect the DSTV dish and the Decoder at home.
Is a similar connection but different configuration.
On top of the cable is a light blue cable called console cable.
The console cable is used to configure the devices.
We shall be seeing that.
Other cables like the dark blue and ash color cable are the LAN cable or u call it Ethernet cable used for
connecting LAN devices like the switches and the computers.
If u want to connect the Computer there to the switch there use the ethernet cable.
Read about cable types in my manual.
Resting on the floor, are 3 special routers waiting to be used when we decide to have another GTB branch
in Lagos.
Pls read and comprehend. It will be useful later.
ARCHITECTURE OF ROUTER.
Router Architecture deals with components of a router. Yes we discus the physical parts of the router.
Because is needed during configuration.
A Cisco router is made up of the internal and external components. The external components is what am
concerned about.
Cisco categorized the ports into 3.
1. The Administrative port
2. The LAN port
3. The Serial port
The Administrative port is divided into 3:
1. The Console port
2. The Auxiliary port
3. The Telnet port
The console port is used to login to the router for configuration. This port is used to configure a physical
router.
You connect a console cable (blue color) from the serial port of the PC to the console port of the router.
Check my image is there. Can u see that cable going down the table to the floor??? Yeah, that’s my console
cable.
The Auxiliary port is also there close to the console port. The port is used to connect to peripheral devices
like game console etc.
The last one is the Telnet port. This port is not a physical port on the router. Yeah we assumed is a port.
Well, it’s an emulation software running inside d router but behaving like a port.
This telnet port is the one that gives us access to the router from a distance. I mean if I have a router in
LONDON, I can stay here in Nigeria and do configuration on it. Yes very possible.
Let’s say am a security engineer to GTBANK Nigeria, I don’t really need to be coming to their office to
configure routers. No pls.
Anytime I need to work on the router I can just use d telnet means to login to d router remotely without
needing to go to the bank.
All this is as a result of the Telnet port.
The other kind of port on the Cisco devices is LAN Port.
As the name implies, it is used to connect to my LAN devices. For instance, the straight through cable is
used to connect the LAN Port of the Cisco router to the switch . Remember the switch is one of my LAN
devices. The switch is where all the computers in ur offices is connected to.
The LAN Port is divided into many types based on speed:
The Ethernet port, the fast ethernet port and the gigabit interface.
The Ethernet port moves at 10mbps
The fast ethernet moves at 100mbps
The gigabit moves at 1000mbps.
We even hv the 10gigabit interface now. This one is used when the files u are trying to move is supper
heavy.
Think of a football match bin played in another country and u are in Nigeria watching it live. Boy the
devices setup in the field to stream the video live on the internet are devices with such a high speed. That
is why u are able to watch d game live as it is happening there.
If for instance, they are using a device with low speed, the consequence is that if Ronaldo shoot a kick, it
will take 5 mins for you to see it in Nigeria. What a nonsense. Yes, because the device sending it to internet
is too slow. But with a high speed device, Bro u will be getting it live as it is happening within a second.
With a high speed device, upload and download become fast.
The last type of port is ur Serial port. This port is used to connect to your wide area network. I mean this
port of the router is what u used to connect to your branch office.
The serial port is a WAN port. Simple.
We have more to discuss about it……
Now that we are familiar with the ports on the routers, next is to start configuring them.
I already told u to download the Cisco packet tracer to follow up in this class.
A Cisco router needs to be configured before it can function well.
Configuration is like giving life to the router.
The interfaces also called ports needs to be activated before it can function well.
You need to assign IP address to the active interfaces before it can function .
This configuration is done by adding commands to the router.
The commands are like codes or languages that routers understand.
When u command the router, it follows ur command.
Routers are intelligent device that knows how to obey commands.
Routers sometimes make us thinking, 🤔is computer more than human being?
We will now be configuring the device called router.
To Configure a Cisco router, first u need to power it on, then connect ur console cable to the console port
of the router and the other end of the cable should be connected to the serial port of the PC.
And the PC must have a configuration software. This software understand Cisco commands.
We have many software listed on your manual but Cisco recommend one particular one called *putty*.
Let’s assume u already download the free putty from Google and Installed it on ur PC.
Click on your putty and it will open an interface for u where u will have to start typing your commands….
Which commands will u be typing…?
The commands are what u will be learning henceforth.
The CCNA syllabus discussed about the various commands needed to control the router. Let’s learn……
Before Configuration note that:
S stand for serial port
e stands for Ethernet port
f stand for fast Ethernet port
g stands for gigabit interface
The ports are numbered just for identification.
For instance, u may see in your router s0/0
Another guy’s router may have it as s0/1
Some may even have it without the slash. E.g s1.
It is clearly written on ur router.
The one u connect ur cable to is what u will configure or activate.
I may be configuring s0/1 today because that’s what my router gives me.
But in the future when UBA BANK invited you for networking don’t think Mr Ali do configure s0/1 so I will
do the same. No no no.
You are to configure what you see on the router.
Let’s start the Configurations proper, for now just be following pls.
Later I will tell u how to do the same at your end.
Once u clicked on the putty software it will open an interface where u will enter ur command.
The router will be asking you,
console 0 now available, will you like to continue with Configuration dialogue?
YES/NO……?
Just type No and continue…….
If u type yes the router will start asking unnecessary questions that u will be like, let me throw this shit
away. Just say No and continue.
The router will then ask u to press RETURN to start Configuration.
Is ok, press RETURN.
RETURN is the same as ENTER key on your keyboard.
Once u do that u will see this mode will appear. We call it user mode:
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