Neil's Network+ Notes & Tips

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Ok guys, I've finally found some time to do this. This is just my way of giving back to the place that has helped and motivated me alot through my certification journey. I trust that this will be a help to all those future Network+ test takers. So here we go!

Intro
First of all, let me state that I will not attempt to cover the entire Net+ objectives or try to put it in a nutshell. These notes are primarily aimed at those hard to rememebr stuff that you NEED to remember. I'll show you the methods I used to memorize tables and other sorts of specs and hopefully, these methods would also be able to help you do the same for future exams. I'll won't be able to cover everything in this one post, so please bear with me as I'm only able to add more as time permits.

Some of the main stuff that I'll be covering includes:
- the famous 'ol OSI Model
- the unavoidable Cable Specs Table
- TCP/IP Port Numbers
- Connection & Connectionless Protocols (Yes, you NEED to know them!)
- essential Wireless notes
- My personal exam prep tips & resources
- other stuff that you need to know, that I can't remember right now......

These are the main stuff that you definitely need to know for now. After I post on each of them, I'll be able to take your requests for other topics. I'll also post my tables in graphic form so that you can save them and use them as study cards for quick revision.........it's also easier on my part to do it that way

Ok, I'll post this up now and please give me a couple minutes so that I can type and post up the first topic. See ya soon!

Disclaimer: Please note that while my methods may not be universal or conventional, they are MY personal methods that I devised and they worked for me. Some would be able to grasp them, others may not. Its all up to you and how willing you are to employ your understanding.

 

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cool, I look forward to it

 

Nice One NEIL

 

Sorry for posting this so late. My ISP was down for quite a while.

The OSI Model
These are some of the main things you NEED to know about the OSI model. First you must be able to remember the sequence of the model. Here are the 2 popular mnemonics for remembering the sequence of the OSI 7-Layer model (see attachment below this post). When read from Layer 7 to Layer 1 its: All People Seem To Need Data Processing. When read from Layer 1 to Layer 7 its: Please Do Not Throw Sausage Pizza Away. It doesn't matter which one you remember, as long as you remember one, you'll know the sequence. I prefer the first one.


Main Functions of Each Layer
Most of the functions of these layers can be derived or remembered through the NAME of the respective layer. The 2 most important layers to study and know in-depth are the Data Link and Network Layers. Remember that. The rest just require a fair overview of how they function. I'll give you their main functions in a nutshell here for quick revision, but you need to consult your study text (preferably the Sybex) for the in-depth notes.......otherwise I'll just be repeating what the book says

Physical - Everything to do with the physical aspect of the network goes on here. Defines the physical network topology. Transmits data in the form of "bits". It also defines the mechanical and electrical specifications for transmission.

Data Link - Defines the logical network topology. Consists of the MAC layer and Logical Link Control (LLC) layer. It takes the bits from the Physical Layer and turns them into "frames". Controls media access method. Provides error correction and detection. Since this is a step-up from the Physical Layer, it uses MAC addresses. It has a MAC layer, so remember: MAC addresses!

Network - Routing, routing, routing! Everything about routing! Switching: packet and circuit. Route discovery: distance vector and link-state. While Data Link deals with hardware addresses (MAC addresses), this is a step-up and deals with logical addresses (eg. IP addresses). Also provides gateway services. Also turns the Data Link frames into "packets". Just remember that any question about routing concerns this layer!

Transport - Makes sure that the data IS transported to you! Deals with flow control, error correction and detection, segmentation of data packets and guaranteed delivery of data.

You hardly need to know in-depth about these, but this is just an overview:

Session - Initiates, maintains and terminates sessions between remote computers. When you see this layer, think: VPN and RAS. Think: connection.

Presentation - Provides everything you need in order for the data to be presented to you on the screen. It converts those packets using encryption/decryption, encoding/decoding, and compression/decompression. Once you see any of those words, know that it concerns the Presentation Layer.

Application - Deals with application services by using other protocols such as: HTTP, FTP, email, etc.


Devices On Each Layer
For the Network+ exam, devices only operate on the first 3 layers. They are:

Layer 1 (Physical) - Well we all know that this layer deals with the physical stuff like cables, their connectors and the physical network topology itself. But what about the devices? Well, remember that word that kept popping up while we were doing A+ 2003 Hardware??? That's right: Legacy. Legacy devices are those old and ancient devices that we hardly use these days. They are: hubs, repeaters and transceivers. A transceiver is also known as a media converter. These devices are old and you'll least find them in a modern-day network. So because of that, just remember that they belong way down at the bottom at Layer 1.

Layer 2 (Data Link) - This layer deals with the modern stuff that we see in most networks such as: NICs, switches, bridges and WAPs. So Physical deals with the old and Data Link deals with the new. Practice saying: "NICs, switches, bridges and WAPs" over and over again. It sounds like a silly tongue-twister, but its effective and helps you remember.......how do you think I remembered?

Layer 3 (Network) - Routing! So what're the most logical devices that work here? Routers ofcourse!


Hope you guys liked this and found it easy to understand and remember. Much more to come!

 

Thanks mate! I hope this (and the rest to come) helps you out.

 

Great reference Neil, now is it......Throw not away Dominos if sausage??....no...err

Rep Left

 

Good blog, rep left

 

Thanks guys glad you found it helpful........I'm working on the other one.

Yea Dullage, people DO get confused like that even though its so simple.........that's why I advised to memorize ONE

 

Hey guys, I've been trying to upload the graphic for my next post all day, but it keeps giving me a "TCP_ERROR Trouble Ticket" everytime. This happenes everytime I try to upload a graphic. Is it possible for me to email the pic to one of the admins and have them attach it to my post? I was trying all day without success and I really have to post this. Can any of the Admins help me PLEASEEEE!!!!!!!!

 

I had the same problem uploading a PDF! I did raise a thread over in the problem/comments section of the forum but no one got back to me

Neil - your better off sending a PM to AJ

it might be the size of the file attachment or something wrong on CF's end. I just know when I cut down the size of the PDF I was uploading to CF it still display the same error message despite having enough space for attachments

Original Thread Problems uploading attachments

 

Oh wait I take that back SimonV has reply but it hasn't solved the problem

 

Thanks for your response UCHEEKYMONKEY, I have alot of space left for attachments and the file size is only 18.7Kb! I even tried filling all the upload slots with it to raise it, but nothing worked. I had this same problem with the first graphic of this post, but when I had tried back a couple hours later it worked. Anyways its not working AT ALL now and I'm really sick and tired of it. I remembered there's this site called Photobucket where you can upload pics, so I joined there and uploaded the graphics there. Hopefully it'll work now.

So lookout for the Cable Specs Table is about 1 minute.....

 

Hm...

 

Wow! I'm really glad you guys liked it so far. Sorry for posting this so late, but I'm having a very hard battle with time, however, I made a committment and I intend to keep it (I ALWAYS do!) I tried posting this earlier, but the Forums were down -- so very glad its up and running now! I then had problems uploading graphics, because I was getting a TCP error. I asked the Admins for help.....got no response (very unexpected!). As I was thinking what else I could do, I remembered there was Photobucket! So I permanently solved the graphic problem for life!

Anyways, its time for my next little lecture on:

Cable Specs
Ok, this took some time for me to write, but for someone like me who has an unorthodox method of thinking and looking at things, it took a while to put my methods into text! But alas hope is not lost! I did it!

In order for you to understand this one, you need to download the graphic below this post BEFORE you continue reading. And then follow it as you read. In order for you to see the "patterns" I had to colour code the details. So I'll only be discussing the details I highlighted and show you their connection. I'll structure these details as points in the form of a list to make things easier. The things that make the Cable Specs Table hard to remember are the 4 big headaches of EACH cable: Cable Class, Cable Type, Speed & Max. Segment Length. I'll beak these down as I take you through the 3 Classes of cables. So here we go......



Ethernet
First of all, let's simplify the obvious and then get detailed. How can you tell whether a cable spec is Ethernet or not? Easy! Just look for the "patterns". What do ethernet cables have in common? Notice that they ALL begin with the 10Base prefix! The number in front of the "Base" indicates the Data Speed in Mbps - that's law! Stick it in your head and always remember it! So in this case, 10Base means that this type of cable only transmits data at a wallopping 10Mbps! So from the time you see a 10Base# on the exam, know that its definitely Ethernet and that it transmits at 10Mbps. That just killed 2 headaches there! Now we only have 2 more headaches: Cable Type and Max. Segment Length!

Now, just as we learned that the number infront the "Base" represents the data speed and the cable class, let me shock you by telling you that the character after/behind the "Base" represents the Cable Type and Max. Segment Length! I'll do these individually:

• 10Base2 - the 2 in some mysterious way means 185m instead of 200m. And ofcourse Thinnet uses RG-58 cables.
  
• 10Base5 - the 5 simply means 500m and Thicknet uses RG-8 cables. This and the above are both A+ foundation knowledge, so no need to explain further.
  
• "T" - Indicates Twisted Pair, in which the max. segment length is ALWAYS 100m - that's law! Stick it in your head and always remember it!
  
• 10BaseT - CAT3 Ahhh.... the "T"......10Mbps-Twisted Pair-100m.....
  
• 10BaseT - CAT5 Ok this is a special case right here in which the Law is bent a bit. This and the above are both 10BaseT, but because this uses a CAT5 cable, it transmits at 100Mbps instead of the regular ethernet 10Mbps as indicated in the prefix. But please note that this is only applicable when the cable type is specified. If the exam asks what's the speed of a 10BaseT cable, it would be 10Mbps. If it asks the speed of a 10BaseT CAT5 cable, then its 100Mbps. Just place special emphasis on this and note the obvious difference, as it gives you the clue to the answer, and you won't have a problem remembering this. The other specs remain the same as above: Twisted Pair-100m.....
  
• "F" - Indicates Fiber Optic cable which in this case the max. segment length is ALWAYS 2Km - that's law! Stick it in your head and always remember it!
  
• 10BaseF - Ok, let's see if you caught on......we already know that its 10Mbps ethernet, but hey wait! I see an "F"! That means its Fiber optic......and since those things travel far, then it must have.......a max. segment length of 2Km! Good job you're catching on! Only 2 more cable classes to go! Once you've grasped this pattern concept, you'll breeze through the rest!

Fast Ethernet
Ok, since this is Fast Ethernet, then we're no longer dealing with 10Mbps. So let's check out our new prefix. Hmmm, 100Base I see......ummm, if I use the concept I learnt above, then the number in front the "Base" in terms of Mbps would now be 100Mbps! No wonder they call it "Fast" Ethernet! So much for data speed and the cable class. Yippeee! I'm actually learning! Now for the 2 other headaches: Cable Type and Max. Segment Length. Now if I remembered correctly, they can be derived from the character after/behind the "Base".......

• 100BaseT4 - Ok, we already know its 100Mbps for sure! Hey, I see a "T"! That means its Twisted Pair and that its max. segment length is 100m!!! But there's a "4" after that.......hmmmm, could only mean that there's 4 pairs of wire in the cable!
  
• "X" - Indicates that the cable medium consists of 2 "things" (for lack of a better term ) But how do I remember this? Well let's look at the obvious "X" itself. The X is made up of 2 lines. Lemme see if my math is correct: \ + / = X ! In terms of Twisted Pair (T) it means 2 Pairs of wires instead of the common 4 pairs. In terms of Fiber Optic (F), it means 2 strands of fiber.
  
• 100BaseTX - There's that "T" again! So If I remember correctly, its: 100Mbps-Fast Ethernet-100m max. segment length! YES!!! But I also see that "X"........that's supposed to represent 2 of something.......hmmm, since I'm dealing with a twisted pair cable, then it could only mean.......2 Pairs!!! Ooohhh.....such moments make me emotional......
  
• 100BaseFX - You wanna piece 'o me? Who do you think you are? You don't know? Ok, lemme tell you! You're a 100Mbps-Fast Ethernet for sure, so you can't fool me. That "F" also tells me that you're a 2Km long piece 'o fiber. And don't try to hide that "X" from me, I see it! You're nothing more than a 2Km long Fiber optic cable running on 2 strands of fiber!!! That's who you are! Mike Meyers, eat your heart out!!!

Gigabit Ethernet
And last, but not least, we come to the final cable class (thank God!). Its called "Gigabit" for obvious reasons. In case you missed that, its hard to miss the 1000Base prefix. So therefore, with this in mind, we're not dealing with anything lower than 1000Mbps or 1Gbps of data speed.

Now since this is fast stuff, we're talking mostly of fiber cables. But since the "F" doesn't appear after the "Base", we can't ascribe the above "F" attributes of being 2Km long. Remember that! The X's in this case have no significance, since its applied at the end of all the names. So forget you see the X's. Also remember that "FX" has NO part in this class! The lengths and cable type varies, so I'll run them through one by one:

• 1000BaseSX - The segment lengths of this varies depending on the micron and Mhz specification of the cable. Don't waste valuable memory trying to remember each. Just know that it uses multimode fiber, has a 1Gbps data speed and segment ranges from 220m, 275m, 500m & 550m with 550m being the most popular, cuz its the longest for multimode fiber. Which brings me to.....
  
• "L" - Indicates Long/Longest cable segment length. So if you're presented with all of the Gigabit Ethernet types: SX, CX, LX & T.......Know that LX provides the longest segment length, especially if its running on singlemode.
  
• 1000BaseLX - Multimode fiber-1Gbps with max. segment length of 550m.
  
• 1000BaseLX - Singlemode fiber-1Gbps with max. segment length 5Km. Always remember that singlemode carries the longest segment length!
  
• "C" - Indicates Copper, which means its NOT fiber and cannot travel very far! There's NO "T" there, so it doesn't travel as far as 100m. Remember this!
  
• 1000BaseCX - Ok let's see: 1Gbps........there's that "C", so its copper cable, and since it only runs at a short distance, then its 25m - which is only useful for wiring closets.
  
• 1000BaseT - Last one! 1Gbps and by now you remember what that "T" means..........that's right! Twisted pair with a max. segment length of 100m!!!

Phew! I feel as if I just wrote the exam! I must confess that this is THE MOST DIFFICULT tip I have ever written (and will ever write)!!! It was very hard for me to put my study method for this into text, but this is what helped me pass about 6-8 actual exam questions! Don't let the length of the post scare you........take your time and read it and you'll find it easy to understand and you'll discover the "patterns" on your own and see the relation........that's why I colour-coded them. I really hope you don't find it hard to understand, because believe me when i say: Its the BEST I could've done to explain it. My only reward for this is going to be when you guys reply that you understood all this.........and that's what I'll be looking forward to reading VERY SOON!!! I trust this helped out ALOT!

 

Ok......I see that you've edited your post........wise idea -- considering you only saw ONE of the topics on my list to discuss

Be sure to check out the rest to come!

 

Excellent thread Neil keep up the good work!

Actually cable lengths always throws me, in some test with regards to fibre cables, some question don't specify if it's single or multimode when asking what is the maximum length. Which is a bit unfair!

 

I learned the 2 came from 200 yards which is about 185 meters.

 

Neil, the site has recently been having some technical issues, which have caused a bit of chaos and a lot of work for SimonV. SimonV is the person responsible for maintaining the sites smooth performance. He is the only person that can lift the bonnet and tweak the carburetor.

In future, please don't include your site technical issues in a thread that is only likely to be read by people interested in the CompTIA N+. Post a 'new thread' in the dedicated forum *problems, suggestions and comments* as SimonV will check in there when he logs in. Alternatively, you could send him a PM.

Hope this helps,

Pete

PS.. excellent thread Neal, i like your approach to memorising minutiae

 

Thanks buddy, I'm glad this is helping you out.........it worked for me!

I had major problems remembering cable specs, that's how I HAD to come up with a method to remember it. Just use the table and remember what those letters mean - that's the most important (reason for highlighting). Because wherever you see the letter appear, the specs would be the same and it clues you to the correct answer.

Remember that the exam is multiple choice NOT fill in the blanks!
All you need is a clue and you've got the answer. Use my study method for spotting the clues in the cable name!

I mostly got ethernet cables on the exam and only about 1 or 2 on fiber -- wasn't anything hard really.......that's why I only post what you NEED to know for the exam. Don't get all too detailed, because the exam asks simple straightforward questions. I trust this helps!

 

Okkkk.......didn't know that one! It actually works out to 628ft I think, so it'll be a *little* over 200 yards. But that creates another mystery as to why 10Base5 means 500 meters, while 10Base2 means 200 yards!

I think its just another way for those people who sets these standards, to make simple things so complicated for "normal" people to remember!

Anyways, like it or not, its just something we all HAVE to accept and no amount of discussion can make them change it to suit us.....