CCNA R&S Certification Exam… a piece of cake…

It was the easiest test I’ve taken since I started preparing for the CCNA R&S Cert…

OK, maybe this comes across a bit arrogant, but that is not what I mean at all, let me explain.

I am not suggesting that the exam is easy, it is not. Anyone who is, or was preparing for a CCNA certification, needs to work hard at it because it is a well known fact that the exam is pretty demanding.
I mean, if you really prepared to pass the exam, and you do pass the exam… you know a lot about networking.

VLSM and Subnetting Practice.

On the last article, we mostly talked about Subnetting theory, however, subnetting is one of those topics which you don’t really understand until you practice, practice and… practice. I mean, you still need the theory of course, but you need just enough theory to get you started with the practice. While practicing, you are going to hear “click!” in your head… many times.

So you want to learn IPv4 Subnetting…

Imagine someone gives you one of those big, 7Oz chocolate bar, and even though you are grateful, you are not going to be eating that much chocolate all at once, right?… right?

Well, luckily you can break away smaller squares off of the bar and eat them one at the time, and that is exactly what you do, until 30 minutes later there is no more chocolate bar… well, you tried.

Think of the chocolate bar in the previous analogy, as a big network space which we need to break into smaller, more manageable pieces… I mean networks, we can accomplish this with subnetting.
Subnetting is the process of breaking or dividing a network space, into smaller, more manageable network spaces.

I am back… oh yes, and I am a CCNA now!

Hi everyone!

As you might have noticed, I have not written any articles on my blog for 3-4 months now, and I would like to offer you an explanation.

I started this blog back in February of this year, as a method of getting ready to take my CCNA R&S certification exam. I thought, back then, that it was a good idea and for the most part, it was.

I learned a lot while researching the topics I was going to write about for my blog, in fact, I learned way more than what is required for a CCNA (read my 3 parts article “IPv6 for future CCNAs” and you’ll see what I mean), but something was not quite right.

Don’t get me wrong, I am not complaining about how much I’ve learned, the issue is that while learning all that information was awesome, the actual writing of the articles (at an acceptable quality level) was taking me a lot of time, and so I felt that I was not moving forward at an acceptable pace, not for me any way.

Also, right about the same time, I found out that Cisco was getting ready to retire CCNA v2.0 for the new CCNA v3.0 exam and I had only until August 20^th to take the certification. So right then I decided to stop writing for my blog and just concentrate on my studies.

So, for the past 3 months all I did was read books, watched videos and Packet Tracer exercises until this passed Friday, August 12^th 2016, when I took the certification exam and passed it with a 94.7. Great feeling!

So, this means that I can start (re-start) writing for my blog and hopefully help some of you who are thinking about becoming certified.

Besides, this time I won’t have to do as much research as I had to do before because I have a little more authority on the subject now, right? I mean, of course I am not claiming that I know ALL about networking because I do not, nor am I claiming that I do not make mistakes because I do, but I have a newly found confidence now, I am after all… a CCNA! :O)

1.2 Select the components required to meet a given network specification.

As you can imagine, there are many aspects you will need to take into consideration when putting together a network, specially if dealing with a large corporate network. It’s simply not the same, configuring a network for a small office with 5 employees than configuring a network for a corporate branch with 5000 employees.
Some of the concepts we need to consider when designing a LAN are very straight forward like physical space, cabling, power source, static IP addressing, etc. and some are more complex like flexibility, expandability, security, routing protocol implementation, dynamic IP addressing, IP sub-netting, etc. Basically, the complexity of a network is directly proportional to the size of the network itself.
Luckily, we are getting ready for the CCNA, and its scope states; “…skills required to install, operate, and troubleshoot small to medium-size enterprise branch networks”, so let’s keep this in mind.

1.1 Purpose and functions of network devices: routers, switches, bridges and hubs.

We are going to start, slowly but surely, building a theoretical network in our minds. In order to do this, we are going to start from the beginning; recognizing all the components of a modern network as well as some not so modern devices. For now, it is going to be a basic description of each device’s function, but we will elaborate on each concept as we move forward. Let’s begin.

Broadcast and Collision Domains.

Terms you need to understand.

Broadcast: In this case, a Data-Link layer (Layer 2) message sent to ALL devices attached to the same network segment.

Collision: When more then one device transmit data at the same time on shared media, the packets collide, data becomes corrupted and after a random period of time, devices have to re-transmit the data.

Broadcast Domain: All devices that a Broadcast message reaches at the Data -Link layer within a network is called a Broadcast domain. A network can have more then one Broadcast domain and a Broadcast domain is delimited by devices that stop Broadcast messages.

Collision Domain: Anywhere within a network where a Collision can occur. The limits of a Collision domain are marked by those devices that break up Collision Domains.

IPv6 for future CCNAs (+), Final Part.

Unicast Addresses: Unique-Local.
Before we talk about Unique-Local Addresses (ULA), let me tell you about Site-Local addresses; it was deprecated in favor of the ULA back in 2004 because the term “site” was too ambiguous, no body agreed upon a clear definition of the term “site”; what was considered a “Site”?
Also, the provability of Site-Local address being globally unique were no that high, as opposed to ULAs.
ULAs are meant to be routed within an organization’s LAN or even WAN, but they are not routable over the public network (Internet), hence, you can think of ULAs very much as IPv4’s Private addresses.

IPv6 for future CCNAs – Part II

In IPv6 for future CCNAs – Part I, we ended the article talking, very lightly, about IPv6 address types. Let´s go ahead and dig deeper into the concepts.

To recap, the IPv6 address types are:

Unicast
One-to-one communication. Unique address assigned to an interface, a packet sent to a Unicast address will be received by one single interface. There are several types of Unicast addresses:

IPv6 – for future CCNAs – Part I

The History:
So we are running out (have ran out?) of IPv4 addresses. They have been with us since the very beginning, they were there during the 1980`s when everything was calm, and they stuck by us during the chaotic growth of the Internet during the 1990`s. There were some rumors, during the 2000`s, that they were going to run out soon, but something called Classless Inter-Domain Routing (CIDR) and Network Address Translation/Port Address Translation (NAT/PAT) saved our butts… for a while.
These 4 little sets of numbers, called Octets, separated by dots were very mysterious, we used to look at them from the corner of our eyes asking our selves; What are they for?… What do they do?… How do they do it?
We were intimidated just by looking at them, and they were just 4 little sets of decimal numbers, numbers that we recognize, that we use every day in our daily lives.