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Cisco CCNA certification proves your professional worth. It tells prospective employers that you can handle the day-to-day work of running a mid- to large-sized Cisco network....
Cisco CCNA certification proves your professional worth. It tells prospective employers that you can handle the day-to-day work of running a mid- to large-sized Cisco network.

The two-exam CCNA process covers lots of innovative features, which better reflect the skills and knowledge you'll need on the job. Passing both exams is your first step towards higher-level Cisco certification, and trainer Jeremy Cioara has mapped these CCNA training videos to the 640-816 test. This CCNA training is not to be missed.

Here's how one user described Jeremy's training: "By the way, Jeremy Cioara has to be by far one of the BEST Cisco trainers I have ever had the privilege to learn from overall. He not only keeps your attention but his energy is contagious and he provides the information at a level where you grasp it rather easily."

The last day to take the 640-816 exam is Sept. 30, 2013. After that date, the only ICND2 exam available will be 200-101. CBT Nuggets has a training course for the 200-101 exam here.

All trademarks and copyrights are the property of their respective holders.
1. Review: Rebuilding the Small Office Network, Part 1 (33 min)
2. Review: Rebuilding the Small Office Network, Part 2 (28 min)
3. Review: Rebuilding the Small Office Network, Part 3 (23 min)
4. Switch VLANs: Understanding VLANs (16 min)
5. Switch VLANs: Understanding Trunks and VTP (39 min)
6. Switch VLANs: Configuring VLANs and VTP, Part 1 (35 min)
7. Switch VLANs: Configuring VLANs and VTP, Part 2 (39 min)
8. Switch STP: Understanding the Spanning-Tree Protocol (28 min)
9. Switch STP: Configuring Basic STP (21 min)
10. Switch STP: Enhancements to STP (29 min)
11. General Switching: Troubleshooting and Security Best Practices (29 min)
12. Subnetting: Understanding VLSM (18 min)
13. Routing Protocols: Distance Vector vs. Link State (26 min)
14. Routing Protocols: OSPF Concepts (30 min)
15. Routing Protocols: OSPF Configuration and Troubleshooting (39 min)
16. Routing Protocols: EIGRP Concepts and Configuration (32 min)
17. Access-Lists: The Rules of the ACL (27 min)
18. Access-Lists: Configuring ACLs (34 min)
19. Access-Lists: Configuring ACLs, Part 2 (48 min)
20. NAT: Understanding the Three Styles of NAT (20 min)
21. NAT: Command-line NAT Configuration (35 min)
22. WAN Connections: Concepts of VPN Technology (33 min)
23. WAN Connections: Implementing PPP Authentication (34 min)
24. WAN Connections: Understanding Frame Relay (28 min)
25. WAN Connections: Configuring Frame Relay (30 min)
26. IPv6: Understanding Basic Concepts and Addressing (34 min)
27. IPv6: Configuring, Routing, and Interoperating (23 min)
28. Certification: Some Last Words for Test Takers (13 min)
29. Advanced TCP/IP: Working with Binary (25 min)
30. Advanced TCP/IP: IP Subnetting, Part 1 (55 min)
31. Advanced TCP/IP: IP Subnetting, Part 2 (22 min)
32. Advanced TCP/IP: IP Subnetting, Part 3 (19 min)

Review: Rebuilding the Small Office Network, Part 1

Review: Rebuilding the Small Office Network, Part 2

Review: Rebuilding the Small Office Network, Part 3

Switch VLANs: Understanding VLANs

Switch VLANs: Understanding Trunks and VTP

Switch VLANs: Configuring VLANs and VTP, Part 1

Switch VLANs: Configuring VLANs and VTP, Part 2

Switch STP: Understanding the Spanning-Tree Protocol

Switch STP: Configuring Basic STP

Switch STP: Enhancements to STP

General Switching: Troubleshooting and Security Best Practices

Subnetting: Understanding VLSM

00:00:00

It's time to move in to everybody's favorite topic and that is TCP/IP subnetting. When CISCO split the CCNA into two separate certifications, the CCENT and the CCNA they also split the subnetting concepts. In the CCENT they introduce subnetting and they even got pretty complex with it, but they didn't go all the way. Meaning there was one piece of subnetting

00:00:26

that CISCO left out of the CCENT testing objectives, and that is known as variable lengths Subnet masking, or VLSM. This is going to be where we talk about VLSM in the ICND part two. But I want to make sure that is familiar with the ICND part one form of subnetting. It's,

00:00:45

it's a method of subnetting that i've been using for quite some time. It's pretty simple but, I also realize that if you haven't gone through ICND part one you're going to be completely confused when you see the style of subnetting that I used here. So what

00:01:00

I what I have right here is my first objective to talk about is to remind you all that we have as an appendix to this series all the subnetting videos that I created for ICND part one. So if you have not seen ICND part one or it's been a while and you need to review before we get into the advanced subnetting, feel free to look through those appendix videos and check those out. Also

00:01:23

with those videos is tons of practice for you, so you can actually practice through some some questions on your own and then review yourself in the answers. Those practice questions and answers are going to be available on nuggetlab.com under it'll probably be under the ICND part one's video series you can download those, no log in required no cost to you at all to work through and practice them so what we're going to do here is the second bullet. Working through a VLSM

00:01:52

scenario. VLSM stands for variable length Subnet mask. It's a technical term but really a simple definition. All it means is that you can change your subnet mask whenever and wherever you want on the network. Now remember what subnetting is. Subnetting is taking one network and breaking it into many networks.

00:02:15

For example, we have 192.168.1.0/24 here, and I could break that into mini networks to address this, this network that you see in the diagram. But notice the statement, it says subnet 192.168.1.0 to address this network, using the most efficient addressing possible. Whenever

00:02:37

you see most efficient addressing possible that means we're going after variable length Subnet masking, which means you're going use custom Subnet masks for every segment of the network. Now, VLSM in my opinion is no more difficult even though it's the most difficult of the CCNA series. I don't really think it's

00:02:56

that much more difficult than any other subnetting problem that we've seen thus far. If you look through the appendix videos but what I will say is it will take longer because it's multiple Subnet problems in one. So let's work through this scenario one network at a time.

00:03:12

So, what I'm going to do is squish that network diagram up in the corner so we have some working space here, and look at the scenario one more time. We need to Subnet 192.168.1.0 to address the network using the most efficient addressing possible. Now whenever

00:03:26

you see that think VLSM and then think the whole key behind VLSM is to start with the largest Subnet. Now looking at that diagram what is the largest subnet? That one, 60 users right there. So we need to start with that one, now this is using the methods that I was talking about in the videos and in the appendices, so again if you haven't seen those videos now's the time to check them out. So we've got 60 users. I'm going to take my 60 users and convert that to binary. Put up our binary chart, 128 64 32 16 8 4 2 1. 60 is a one in the 32 one in 16 that's 48 add another eight that would be 50. I shouldn't have done this in my head. 48 plus eight a is 56 so add a four and we've got our 60. So there's 60 in binary. Zero zero one one one one zero zero. Now you might remember that we're not... After the exact binary number

00:04:38

we're mainly concerned with how many bits it took to get the number 60. The number of bits is six, so we can't get the number 60 with any less than six bits. So, move on to step two. Step two is to write the original Subnet mask in all binary. So a /24 is 24 ones. So a whole bunch of ones that's, imagine that being 24 of them. And then eight zeros. One two three four five six seven eight. Now we've got

00:05:05

60 that we converted to binary are we after creating more networks here or saving the hosts. We're looking at 60 after the users I need to save some hosts. So I take right to the left one too three four five six the other two can become ones. I've saved my six zeros. So with that in place my new Subnet mask

00:05:31

for the 60 user network will be slash 26 or two 255.255.255 and this in decimal over here is dot 192. The lowest network bid is my increment. That's that guy it is a 64. So, I come down to my third step and I can find my network ranges. So I go 192.168.1.0 that's where I began and then I'll just go to 1.64 and actually stop right there. How many networks of 60 users do I need? Looking at this diagram there's just one. So I can fill in

00:06:13

the end range that would be 192.168.1.0 through 63 and there is my network range. What I'll do is on my network diagram I'll notate as matter of fact, let me type it so it's a little neater. Right here will be 192.168, change that font just a moment. .1.0 through 63 slash, and I'll put my Subnet mask, 26. Let me increase that font size a little bit. There we go. I'll drag

00:06:48

that right here. Good so we've got that which is now my first VLSM subnet. With that in place the whole key to VLSM is now do it all over again. So I'm going to take what I've done oops, the one Subnet I have there. Let me select the right field there. There we go. Erase it and start all over now you can see I've got one subnet

00:07:15

solved. Now let's move to the next biggest, you see VLSM you start with the biggest Subnet and you work your way down. So I'm moving on to the next biggest which is 20 users. So we'll take twenty, convert that to binary. Oh, should've saved the binary chart. Save the chart. So

00:07:31

32, 16, 8, 4, 2, 1. And I'm going to say 20 in binary is zero. Oh, here is my first one right here. One good grief. One and one the rest of these are zeros so 20 in binary is zero zero zero one zero one zero zero. It takes five bits to get the number 20. So step two is now to take my original Subnet mask /24 write that in binary, 24 ones and we're writing this as if I had never done any subnetting in the first place.

00:08:07

There's my eight zeros. Now I'm, again after saving my host because I am after 20 users, five host bits so right to left one two three four five remain zeros, the rest can become one my new Subnet mask for that portion of my network is /26 or wate, no, /27 because there's 27 ones or in decimal it would be two five five dot two five five dot two five five and that would be.224 Lowest network bid is my increment. Convert that back to decimal.

00:08:40

That would be a 32. So step three, is to start off with what I was given 192 168 Just as if I had done nothing and start adding 32 1.32, 1.64. Now wait just a second. Let's fill in some end ranges here. I'll go through 31 through 63. Now can I use any of these? No. Cause they're already used right here. You see that one is zero to 63 three so that is unusable. That is the unusable. I need to

00:09:18

start off with where I left off which is 64 and keep adding 32. So 96 .128. Now I only need two networks of 20 users each so I can go in there and just stop after these two ranges. This will be through 95 and this will be through 127. You're seeing kind of how this works? So I picked up where I left off. Zero through to 63 is used up right here. I have, let me grab my text tool. Going to copy this guy up here so we'll notate.

00:09:56

192.168.1.0 or this will be let's change that, 64 through 95/27. Good. And then I'll assign that second range over here to these 20 users. This will be 192.168.96 through 127/27. Good. So now we've got both of those subnets completed out there the 20, the two subnets of 20 users and if you look, well there goes all our work again. It's gone because we've now

00:10:33

addressed the 60 users and the two networks of 20 users but there's still one more that's very easy to forget. You see the WAN links. How many users are on a point to point WAN link? Two. There'll never be any more than two users on a point to point WAN link. That's the definition of point to point. So I'll start over again

00:10:52

for my last network range and that is two users. So, two users. Let me put my binary chart back up there. One day I'll learn not to wipe it out. 8 4 2 1. Two users that would be one zero so it takes two bits or zero zero zero zero zero zero one zero. Two bits to get the number two.

00:11:16

So I write my original Subnet mask in all binary. /24 whole bunch of ones, 24 of them, dot one two three four five six seven eight zeros. Now I'm saving the host because I have two users so those two remain zeros the rest of them become ones so I have six ones and two zeros leftover. My subnet

00:11:38

mask moves to a slash 30 or if I were writing in decimal, it would be two five 255.255.255.252 two fifty two. My increment, lowest network bit converted back to decimal is four. So now I go to my step three which is finding my network ranges. I can go 192.168.1.0 zero dot one dot four dot one dot eight. Now,

00:12:06

hang on just a moment. Can I use any of these zero four, zero through three, four through seven? No. Because they're already used up right here. As a matter of fact I could keep counting back 4 12 16 20 twenty and so on and I'd go through all these ranges and all of these and they're all used up. Now if you if you don't feel comfortable

00:12:25

doing this, don't but what I would say is it's a lot easier to just go dot dot dot and pick up where you leaved off. You notice a right here we ended at 127 so the next one would be dot 128. 132 136 140. If you keep counting by a four you'll eventually get to 128. And you don't want to do that as efficiently as possible without filling the page with numbers. So I can now fill in my end range, that would be 131, one, one thirty five, one thirty nine. So, let me

00:13:06

grab my subnets I have been using right here. Copy and paste them I will assign this WAN link 192.168.120 twenty through 131/30. There we go. We'll use over here one thirty two through one thirty 135/30. And then finally up here one thirty six through one thirty nine slash thirty. And that

00:13:47

is addressing a complete network using VLSM. Now, if you look at this it's pretty amazing because we've addressed this whole network and barely used over half our network range. If we didn't have VLSM we, we couldn't do this. I was just thinking of that. We, this would

00:14:04

be impossible because we'd have to -- if we had -- could only use one Subnet mask which is what VLSM is trying to prevent If we could only use one Subnet mass we have to figure it for the biggest one. And if you go in increments of 64 you'd only get four networks and you can see we would need more than four networks to complete that scenario. So VLSM is the only way that we could effectively

00:14:26

address that network and it is very efficient. Now, there's a couple notes want to add onto this before, before we wrap things up. The first thing I'll mention is why we started with the largest Subnet first. If you think about it if we would have started with the smallest or, or some other Subnet first there would be waste. Notice it says use the most efficient addressing

00:14:48

possible. Well let's say we started with this WAN link Subnet right here. Zero through three four through seven eight through that would be through eleven if we were to continue that for WAN links. So that would be if we started with the smallest and that

00:15:00

would kill this this first group up to the IP address one 192.168.1.12. Now, let's say we move to this 60 user Subnet after that. Well our first range would be zero through 63 but we couldn't use that because these were already used up. The WAN links already killed zero through 11 which would overlap so we would have to go with 64 through, what, that would be 127 for this range right here which you would have a waste. You would waste from 12 through 64 because you started with the smaller Subnet rather than starting with the largest Subnet. So that is why we start

00:15:37

with the smallest one first. The second thing I want to mention while I've got the diagram up is VLSM like this looks beautiful on paper. But think of real world with me here. If this Subnet up here our 20 user Subnet had a sudden hiring spree and brought on 50 new employees well that would blow up your whole IP addressing scheme because you would exceed your 20 users Subnet, which only handles up to about 30 users and you have to re- address the whole network so when you're doing this in the real world always use room for growth.

00:16:16

So, so don't Subnet it so tight to where it looks perfect on paper but only lasts a good year before you have to re-address the whole network anyway. And, let's see what else can I mention about this? VLSM is very commonly used right here on the WAN links, most of the organizations that I've seen on all the point to point WAN links will use the /30 and on the LAN they'll use something easy like a /24. Even doing something that simple is using VLSM that leads to the big point which means if you use VLSM you must have a class less routing protocol and those include RIP version two OSPF, EIGRP ISIS and that's it that I can remember off the top of my head.

00:17:08

The ones it does not include are the two class full protocols let's go that way. Class full is RIP version one and the old IGRP which CISCO no longer manufactures. So classless routing protocols only will support that kind of environment. So, that is variable length Subnet masking. Not to bad, right?

00:17:27

It's just multiple Subnetting problems in one. Yes it does take a little bit more time to do but it's really, once you get past the idea of doing more than one Subnetting problem it's not too bad. Now, if you're preparing for the exam you might be wondering how would they ask a question like that on the test? Well what I would say is think drag and drop. Think of having a picture of a

00:17:51

network diagram and all these blanks where you can put Subnets, and then they'll say Subnet this for the best possible or most efficient way and have all these options of Subnets over on the left inside that you can drag and drop to complete the network diagram. So when you're doing it that way sometimes

00:18:07

you may find it more efficient depending on your skills to reverse engineer all the Subnets on the left hand side to find what would be the what would you know satisfy the requirements or you may find a more efficient to do what I just did and do a complete DLSM prompt. It's your choice. So we saw first

00:18:23

off that there are more Subnetting videos into the apendeces since my recap here. If you do need more Subnetting practice and then we worked through a complete VLSM scenario using one class C Subnet with multiple Subnet masks to address the whole network. I hope this has been informative for you and I would like

Routing Protocols: Distance Vector vs. Link State

Routing Protocols: OSPF Concepts

Routing Protocols: OSPF Configuration and Troubleshooting

Routing Protocols: EIGRP Concepts and Configuration

Access-Lists: The Rules of the ACL

Access-Lists: Configuring ACLs

Access-Lists: Configuring ACLs, Part 2

NAT: Understanding the Three Styles of NAT

NAT: Command-line NAT Configuration

WAN Connections: Concepts of VPN Technology

WAN Connections: Implementing PPP Authentication

WAN Connections: Understanding Frame Relay

WAN Connections: Configuring Frame Relay

IPv6: Understanding Basic Concepts and Addressing

IPv6: Configuring, Routing, and Interoperating

Certification: Some Last Words for Test Takers

Advanced TCP/IP: Working with Binary

Advanced TCP/IP: IP Subnetting, Part 1

Advanced TCP/IP: IP Subnetting, Part 2

Advanced TCP/IP: IP Subnetting, Part 3

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16 hrs 32 videos

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Jeremy Cioara
Nugget trainer since 2003