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IPV4 addresses are shown in dotted decimal format. as you can see the picture we have for portions of 4

the IP address and portions are separated from them with a dot. 5

That's why we use dotted decimal format for the IP addresses. 6

And but behind the scenes IP addresses are 32 bit addresses 7

we're going to make a practical training 8

After this video on the board about these calculations. 9

And I'm going to show you how we calculate these numbers.Step-By-Step on the board. 10

Let's take a look to binary to decimal conversion. 11

We have two examples and we have two numbers and here is an example and I'm going to use this for example 12

two. 13

I'm going to use this. 14

These are binary values of the numbers ,In the binary values 15

I can use just 0 or 1, but the decimal values I can use the numbers from 0 to nine. as you know OK let's 16

take a look to the our examples for the first example. 17

I'm writing this number as you can see and I'm writing the example to also one of those 0 1 1 111 10 18

and let's make our conversion if I want to convert this binary value to decimal what 19

I'm doing is i am writing 20

The two the zero , two the power one, two the power two Three four five six and seven 21

and I'm calculating these numbers two to the power seven 128, 6 64, 5 32 ,16 8 4 2 and 1 the last step 22

i am multiplying the numbers 23

and adding them together. 24

For example 1 is multiplied with 128, twenty eight is sixty four with one, 32 with 25

zero and I'm adding these numbers together. 26

And here is the decimal value of the 1 1 0 1 1 0 1 0. 27

This is two hundred and eighteen 28

and if I want to convert from decimal to binary, what I'm going to do ? here we have a reverse logic, for example 29

if I were to convert 225 to decimal, I'm dividing the numbers 30

serially to the two, 225 divided by two. 31

And as you know that quotient is 112 and remainder is 1, and i am doing these steps.. 32

And I am writing the binary number from bottom to up as you can see that 11100001 33

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And let's take a look to the eight I'm dividing seriously two to eight divided by two is four. 35

And remainder is zero 36

then four divided by two, result is two and remainder is zero again, 37

two divided by two 38

quotient is one and remainder is 0 again 39

and one divided to two, quotation is zero 40

and remainder is 1 this time. and I'm writing from bottom to up again and it's 0 0 0 0 0 1 0 0 0. 41

All right. 42

Let's take a look to the subnet mask. 43

Now subnetting is used to divide the network 44

and subnet mask is a bit mask that can be used 45

to separate the bits of networks identifier from the bits of the host identifier. 46

We should use serial ones to represent the subnet mask 47

and we have some exect values that we can use to represent subnet mask 48

I'm going to show you that. 49

But we can represent a subnet value as in slash X format or in a format like this. 50

Like an IP address I'm going to show you now. 51

Here are the valid subnet mask values. 52

As I told you in a previous slide we should use 53

.. 54

00. 55

I'm sorry 1111 111 11 1 111 56

1 1 1 1 ...... 57

And as you can see that I cant use a separate one between zeros when I'm writing a subnet mask 58

all these can be zero, 59

all that can be one but that shouldn't be a valid 60

subnet mask OK. 61

I cannot separate these guys from each other. 62

Ones are their best friends and they never lived together. 63

If you convert this binary values to decimal values 64

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you can get these numbers easily and if you convert this one this is going to be 255 for example. 66

You can give it a try. 67

and lets take a look to network ID. network ID is calculated with logic "and" process of the IP address 68

subnet mask. 69

Let's take a look at what and process is. 70

But please keep in mind that in our previous section we have talked about that if the devices are in 71

the same network or not 72

if devices are in the same network they should have same network IDs. 73

If NIDs are same. 74

I never send packet to the default gateway and I can connect over a switch. 75

For example this is PC one and this is PC2 and this is PC three 76

let's say that we have an IP address of two and this is 77

and let's say that this is 78

Let's say that we have all the same Subnet Mask 79

255 255 255 0 80

If I want to calculate the network ID I need logic and of IP address and subnet mask 81

So what that mean. 82

I'm going to show you with a practical training. 83

This on the board. 84

So after the session you're going to check what I mean in here. 85

But please keep in mind that first host address is calculated by adding one to the network. 86

And here is how we calculate the "and" process .If two bits that I'm using with "and" are zero 87

Or even if I have a zero for the "and" process the end result will always be the zero. 88

Please keep in mind that the and is one when both bits are 1 89

OK. 90

It's 0 on the. 91

Any other way. 92

But if it's 1 1 my result is only 1 93

and here is how I can make a dynamic IP configuration for host.i am opening my Internet Protocol 94

version 4 properties on my PC and I'm choosing obtain an IP address and DNS server automatically 95

so I can get a dynamic IP configuration from a DHCP server.And here is how I can make a static IP configuration for host, 96

in this time I'm choosing to use the following 97

IP address method and I'm writing my values manually instead. 98

And here are the IPv4 host communication types. 99

We have unicast multicast and broadcast which we have talked about in our previous sections .if i want unicast 100

i am sending packet directly to B 101

if a want multicast i am sending my packets to b or c but not to d , if I want to send the broadcasts 102

I'm sending my packet to all of them. 103

So how I can make the IP v4 unicast communication? Let's see that: if computer a wants to communicate 104

with computer c, he is choosing the source ip as his own address, and destination 105

IP and packet is going only to computer C , not to computer B 106

... 107

if i want to send a multicast to the network that I'm in reserve multicast communication 108

IP addresses are : 109

224.0.0.0 and 110

224.0.0.255 111

I need to send a packet to these IP addresses if I want to send the multicast to my network. 112

And here is the private IP addresses and IP classes. these IP addresses private IP addresses are used for 113

local area network communication and they're not globally routable. 114

That means I cannot use this IP address range on the Internet because they're not globally routable 115

And we have a class a class B and class C IP addresses. 116

but classfull adresses are legacy anymore. 117

And if I...For example if I'm using Class A I can use these IP addresses. 118

I just can use the subnet mask, if I'm using Class C I can use this range with the subnet mask but 119

this is legacy and any more we are using classes adressing for example I'm using these private IP address 120

adressing for example I'm using these private IP address range but I can use these subnet mask too without 121

any problem. 122

So let's take a look at the variable length subnet mask.subnetting a network to make for the most 123

efficient use of all of all of the bits means VLSM. 124

And that's the classless adressing that i I talked about for example you are using a range in this class 125

c range, but you're using an another subnet mask that's not in the table of the previous slide. 126

So let's take a look to the IPV 4 broadcast communication 127

these PCs have these IP addresses 1.10, 1.20, 1.30 and here is the default 128

gateway for them and network IDs for these PCs is 129

192.168.1.0, 130

as I told you that I'm going to show you that on the board 131

how i calculate the network IDs detailed and the broadcast address is 132

for this network 133

is this one. I'm going to show you that again. 134

how we calculate this on the board. 135

And because of that the packets destined to this IP address are sent to all hosts as communicate. 136

For example if pc-1 needs to send the broadcast of my network using that source IP as 1.10 137

and destination as the 1.255 138

and let's take a look at the regional internet registries. 139

These guys manage the allocation and the registration of IP addresses within a particular region of 140

network. 141

For example we have APNIC we have AFRINIC in Africa we have ARIN we have LACNIC and we have RIPE 142

... 143

And it is time to talk about the IP version 6. as we talked about in our previous sections 144

IPv4 addresses are about to finish and need will increase for IP addresses by IOT as you know and 145

IPV6 provides us much more address space. 146

As you remember that it was like 147

340 andecilion and we don't need NAT anymore 148

IP addresses, IP version 6 addresses are shown in the hexadecimal format. 149

But it's too.... 150

I'm sorry It's one hundred and twenty eight bit addresses behind the scenes 151

in hexadecimal format you can use 0... 9 after a b c d e f 152

and we can also simplify the IP version 6 notation 153

We have two rules about this. 154

First one is the zero suppression rule : 155

strip off all leading zeros.If we have a leading zero in my Ip version 6 adress I can strip off this. 156

example. 157

in here as you can see I have a leading zero , here I have leading zeros so I'm stripping off them 158

and I can write this 0db8 and I can write just db8 instead of 0db8 159

The first rule that I can use 160

and the second thing is the zero compression rule. 161

And replaced the contiguous groups of 0 with a column column. 162

please keep in mind that I can make it just one time 163

As you can see that we have a continuous groups of 0 and I'm writing just the column column instead 164

of this one 165

Let's take a look to IPv6 prefix-length, which is used to identify how many bits 166

of IP version 6 address are there in network part.And as you can see that we have these number 64 which is 167

represented to you to identify that the first 64 bits are in network part.IPv6 doesn't use 168

dotted decimal subnet mask notation 169

we can just use the slash X notation instead of the other one and in IP version 6 we have unicast communication 170

,again multicast connection again.But we don't have broadcast communication 171

in version 6 172

but we have anycast communication instead of the broadcast which means one to any as you can see that in the picture. 173

IP version 6 unicast is the same with the IPv4 unicast. 174

If computer A wants to send a unicast msg to C 175

that's using Source IP as it's own IP address and destination IP as the computer C2s IP version 6 address 176

and we have some unicast address types of the IP version 6. 177

They are global unicast link local loopback unspecified address unique local and embedded IP v4. 178

Let's take a look to the IP of ipv6 global unicast 179

first ipv6 global unicast address is globally 180

That's a similar logic to the IPV4 for public address.And this address is routable on the Internet too 181

and here is the address range of the IPV6 global unicast. 182

And here's how we can configure this. 183

Please keep in mind that if you're making IP version 6 configuration, first thing you should do is using 184

IP version 6 unicast routing command and make your device ready to make IP version 6 routing then 185

you open the interface that you want to go in with interface command interface fe 0 0 then you type 186

the IP address.If you would configure IPv4 for you type IP address blah and 187

blah blah blah and blah blah blah. 188

This is the IP address that you use and this is the subnet mask. 189

But if you're configuring ipv 6 you're typing IPV 6 address instead of IP address. 190

That's it. 191

The rest is the same IP address and the subnet mask. 192

We can make the IP version 6 host globally unicast configuration dynamically in two ways. 193

The first way is stateless address auto configuration. 194

The second method is dhcp version 6 in the stateless address auto configuration router can send the IP 195

IP address. 196

prefix length and default gw information to the clients , in dhcpv6 197

server sends the IP address. prefix length, gw, dns and domain name information 198

to clients. 199

Let's take a look at the SLAAC. the router can offer three types of informations as SLAAC type. 200

The first one is SLAAC only 201

if router sends SLAAC on the message. 202

That means use the information that router sends only. if router offers SLAAC and dhcpv6 203

That means use the information that router sends and get the others from the dhcpv6 server for 204

example use the information that I'm sending you like IP address and prefix length and Gateway but get 205

your DNS from the dhcp version 6 server and third method is dhcpv6 only. 206

And in this method router is offering that.I'm sorry man I cannot offer you anything. 207

Just use the dhcpv 6 server to get all of your informations Let's see that with an example for 208

Let's see. 209

With an example host is saying that hey router I need IP version 6 options man ! router gets the message. 210

And can offer three types of messages in the first message SLAAC only router saying that here is your 211

IP prefix length and gw , in the second method 212

router is offering that here is your IP. 213

prefix length But ask the DHCP version 6 server for the DNS and domain name and here's the last step. 214

Router can also say that I'm sorry my friend, I don't have anything for you as the DHCP version 6 server about all 215

And here we can dhcp version 6 216

6 you can take a look to the version 6 options in those example host is saying that hey router 217

I need IP version 6 options 218

router can offer that : 219

Here is your IP, prefix length but ask the dhcp version 6 server for DNS and domain name . host gets the IP and 220

prefix length from router and ask DHCPv6 server for DNS and domain name. 221

the other unicast type that we are using in IP version 6 is IP version 6 local unicast .that provides communication 222

on the same local link. 223

That's a similar logic to IP version 4 private addresses. 224

And this address is assigned with prefix 225

fe80::/64 although being defined as the block of this block and link 226

local unicast addresses are also being used for the next hop calculation in routing protocols and interface ID 227

can be randomly created or can be created. with the EUI-64 process 228

which we're going to examine in the next slide . as you can see the IPV6 link local 229

unicast has two portions 230

first portion is these address space. 231

This is the remaining 54 bits and in the second portion we have interface ID and we can calculate the interface 232

ID randomly or with EUI process. 233

And let's take a look to the EUI 64 process. 234

The first step is F F E E to the middle of the client's MAC address. 235

Let's say that this is my MAC address 0 0 0 C 2 9 2 c 0 0 c 0 3 4 so on and the 5 and the middle 236

of the mac address is here. 237

and I'm ejecting an F F F E to the middle of the address. 238

Then I need to reverse the seventh bit for example. 239

If so it is 0. make it 1. 240

If it's 1 make it 0 and establish the 64 bit device identifier. 241

And I'm going to 242

here 0 0 and I'm writing 0 0 243

this is 0 0 and I'm reverting 7 bit, my 7th bit is zero. 244

But I'm reverting it to one and as you can see that here is still 0 which presents here and here represents too. 245

And here is my device identifier. 246

and we have loopback, unspecified address, unique local and embedded IPv4 address types. 247

embedded IPv4 helps transition to IP version 6 , unique local is used for a local addressing, unspecified 248

address is used when the device doesn't yet have a permanent IP version 6 address and loopback is used 249

for sending packet to itself by a host. 250

If I want to display the IP version 6 routing table, I'm using the show IP version 6 route. in a router 251

IP version 6 routing tables and IP v4 routing tables are kept separately. If I want to display this, 252

I'm using show ip route command but if I want to display the IP version 6 routing table I need to use 253

the show IP version 6 route command. 254

But we have the same logic in the routing table as you can see that as you will remember that means 255

connected. 256

That's local That's EIGRP and I have also my networks and I have my next hops that's the same logic with ipv4 257

routing table. 258

Let's take a look to the where to find and troubleshooting type connectivity. 259

The easiest method that I can verify and troubleshoot the IP connectivity is the ping command. 260

For example if I want to check the reachability between PC one and PC2 I can use ping command in PC1 261

I can use that ping 0 3 and check that if I have reachability to PC 2 or not 262

I can also use the extended ping too which has another features like 263

How many times I can ping, I can specify datagram size and timeout and sth like 264

that. 265

And here is output of ping command 266

For example in here I'm seeing the successful ping because I'm getting a reply from the remote device 267

and we are happy as you see 268

if you see an output like this request time out 269

That means that the remote device is not sending a reply to us and that means here's the bad news. 270

Time to cry. 271

Rquest time out. 272

And we have also traceroute command to verify connectivity traceroute is used to test 273

the path 274

hop by hop for example if I want to test the Path from PC1 to until here I can use from PC one to tracert 275

10.0.0.1 command. 276

This will check the path hop by hop 277

And will say me if there's a problem on the road or not. 278

Please keep in mind that if I'm using trace routes from a PC I need to use tracert 279

But if I want to use trace route from a network device such as a switch or router I need to use trace 280

route command in and and traceroute has also extended options too 281

And here is the command the output of the trace route. 282

For example tracert 283

this IP address we can write the domain name or the IP address too. 284

And here is the path that I'm using when I'm trying to reach to this IP address. 285

And that means trace complete and that shows that you have reachability and there's no problem. 286

But in this scenario as you can see that I'm going to this ip add., here too , here too 287

But here is the last node that I can go when I'm trying to go to the IP address. 288

And as you can see that it's time to cry. 289

Here is bad news, if I need to troubleshoot that way I don't need to check the nodes between here I need to 290

go I need to take a look at the further of here. 291

and we have also debug command which provides real time troubleshoot about protocols 292

IOs processes and events. 293

But please keep in mind that you should use debug command very carefully because debug command may 294

cause 295

Hi CPU usage. 296

If you want to stop the Debug that you open you should perform. 297

u all command and and that's your best friend. 298

And for example debug IP X is an example usage of the command for example debug IP RIP 299

when you are debugging RIPmessages 300

and we have another great tool that I can use. 301

That's the terminal monitor command which is used to display log messages when connected via telnet or Ssh 302

to the device. 303

Log messages are displayed by default for just console connection. 304

And if you want to view them in Telnet or SSH session you need to type terminal monitor.