-: Virtual network devices 2 2
represent a major shift in the way 3 3
data centers are being designed, 4 4
fielded, and operated. 5 5
We have started virtualizing everything out there. 6 6
We started with virtual servers 7 7
and now, we're in the virtual routers 8 8
and switches and firewalls. 9 9
We even have virtual desktops 10 10
where you don't have to have 11 11
a physical computer anymore 12 12
and instead, you operate everything 13 13
through a web browser. 14 14
We also have VoIP, 15 15
which is virtualizing voice and telephones. 16 16
And we have software-defined networking 17 17
and cloud computing. 18 18
Now, we're going to talk about all of these things 19 19
in this section of the course. 20 20
Let's talk about virtualization first. 21 21
Virtual servers have the ability 22 22
to allow multiple virtual instances 23 23
to exist within a single physical server. 24 24
Now, if I have one hardware server, 25 25
as shown here on my screen, 26 26
I can end up having six or seven 27 27
or eight virtual servers 28 28
residing inside of it. 29 29
In this example, I have a file server, 30 30
a network server, a mail server, 31 31
a database server, a web server. 32 32
You're going to start to get the idea here. 33 33
Now, all of those servers 34 34
can be running the same or different 35 35
operating systems, as well. 36 36
They might be running Windows or Mac or Linux, 37 37
all of those simultaneously 38 38
on this one piece of hardware. 39 39
This allows us to have a lot 40 40
of our cost savings for an IT budget 41 41
because you only have to have 42 42
one physical computer or server 43 43
and this might cost me $10,000 or $20,000, 44 44
instead of having five or 10 of these 45 45
$10,000 or $20,000 servers. 46 46
This is going to allow us to consolidate 47 47
all of our physical servers, 48 48
saving us power, space, and cooling costs as well 49 49
inside of our data centers. 50 50
Now, the physical hardware can actually use 51 51
multiple network interface cards 52 52
and bind them all together 53 53
using something known is link aggregation. 54 54
And this can be used with other techniques as well 55 55
to increase our available bandwidth 56 56
because if I have one server 57 57
that's running six or seven 58 58
or eight virtual servers, 59 59
one of my biggest limitations 60 60
is going to be network connectivity. 61 61
The machine and the operating system 62 62
that we're going to use 63 63
on this physical piece of hardware 64 64
is what's known as our hypervisor. 65 65
This is a specialized software 66 66
that enables virtualization to occur 67 67
on the physical machine. 68 68
Now, the hypervisor is going to be 69 69
the software that emulates our physical hardware 70 70
for each of those six virtual machines inside of it. 71 71
They are going to pretend and think 72 72
that they each have their own physical hardware. 73 73
But that physical server that they're seeing 74 74
is actually just software 75 75
that the hypervisor is giving to it. 76 76
Now, this is what's known 77 77
as a virtual machine monitor or a VMM. 78 78
Now, what are some examples 79 79
of popular hypervisors or VMMs? 80 80
Well, one of the most popular ones 81 81
is VMWare's ESXi, 82 82
which is a great freeware program 83 83
that anyone can use. 84 84
There is also Microsoft's Hyper-V. 85 85
There is Virtual Box, which again 86 86
is another free open source product. 87 87
And of course, VMWare's Workstation 88 88
if we're doing it in a desktop environment. 89 89
Now, there are two different types 90 90
of hypervisors out there 91 91
called type one and type two. 92 92
Type one hypervisors 93 93
are going to be where you have the OS, 94 94
the operating system, 95 95
sitting on top of your hypervisor 96 96
and that's sitting directly 97 97
on top of the hardware. 98 98
Now, when you're dealing with type two, 99 99
this is where you have a hosted environment. 100 100
For example, I have a Macintosh desktop 101 101
and I run Virtual Box in it. 102 102
So, on my Mac hardware, 103 103
I'm running a Mac operating system. 104 104
And then on top of the Mac operating system, 105 105
I'm running a hypervisor 106 106
known as Virtual Box, 107 107
and inside that hypervisor, 108 108
I'm running Windows. 109 109
Now, this is going to take up 110 110
a lot more processing power 111 111
but it works really well 112 112
when dealing with a desktop environment. 113 113
Now, for servers, on the other hand, 114 114
it's much better to go and use a type one 115 115
because I'm removing that extra layer 116 116
of operating system, 117 117
in my case, that Macintosh operating system, 118 118
and doing what's known as a bare-bones hypervisor 119 119
or bare-metal hypervisor 120 120
that just runs the hypervisor 121 121
as the operating system. 122 122
And then, I can run the other operating systems 123 123
that I want to host, 124 124
like Windows Server, Mac, or Linux, 125 125
inside the hypervisor. 126 126
By removing that extra layer of software 127 127
inside of the type two by moving to a type one, 128 128
I am going to get better performance. 129 129
Now, next thing we need to talk about 130 130
is virtual storage solutions. 131 131
With all these virtual servers, 132 132
I have to have a place to store all of their data, 133 133
and that can be really hard 134 134
if you only have one physical server. 135 135
So, we might look at things 136 136
like a network attached storage device 137 137
or a storage area network. 138 138
Network attached storage or a NAS 139 139
is a disk storage that's delivered as a service 140 140
over your TCP/IP network. 141 141
For example, here in my offices, 142 142
we have two NAS servers. 143 143
These each have a bunch of hard drives 144 144
in our network and essentially allows 145 145
anyone in the office to access it 146 146
and use it for file storage 147 147
over our TCP network. 148 148
Now, the second way of doing things 149 149
is using a SAN, or a storage area network, 150 150
and this is becoming very common 151 151
if you're using virtualized servers, 152 152
like a data farm like Amazon Cloud Services 153 153
or Google Cloud or Azure Cloud 154 154
or something like that. 155 155
When you have a storage area network, 156 156
this is a very specialized type 157 157
of local area network 158 158
that's designed for data transfer and storage. 159 159
They use fiber optic cables because of their high speed 160 160
and they transfer data at a block level 161 161
with a very specialized protocol 162 162
instead of relying on a TCP/IP protocol 163 163
like you use with a NAS. 164 164
This allows it to become much, much faster 165 165
in a standard NAS, and that's why 166 166
storage area networks are used 167 167
when you're doing a lot of heavy server activities 168 168
and you need a big area of fast storage. 169 169
Now, there is a third way 170 170
of doing storage over a network, 171 171
and this is known as a fiber channel or FC. 172 172
Now, fiber channel can also be fiber channel 173 173
over Ethernet, FCOE, 174 174
or it's also known as iSCSI. 175 175
Now, a fiber channel is a special purpose hardware 176 176
that provides one to 16 gigabits per second 177 177
of storage area network speed. 178 178
So, it's basically a specialized type 179 179
of storage area network. 180 180
Fiber channel over Ethernet 181 181
removed the need for specialized hardware 182 182
and instead, ran your fiber channel 183 183
over a regular Ethernet network. 184 184
This allowed you to kind of put up 185 185
this bundleness over a standard TCP/IP 186 186
or Cat5 or Cat6 network, 187 187
and that would help you reduce the cost 188 188
and make it easier for the solution 189 189
to be implemented in your network. 190 190
Then, we have this thing known as iSCSI, 191 191
and iSCSI is the IP Small Computer System Interface, 192 192
And at a very low cost 193 193
and it's built using Ethernet switches, 194 194
but that also makes it have a limitation 195 195
of less than 10 gigabits per second 196 196
because again, our Ethernet, 197 197
the fastest place of Cat6a 198 198
or Cat7 is going to be limited 199 199
to 10 gigabits per second. 200 200
So, when you're dealing with iSCSI, 201 201
it is slower but it is going to save you 202 202
a bunch of money cause you don't have 203 203
to deal with the fiber channel stuff 204 204
and the dedicated hardware. 205 205
This relies on configuration 206 206
that allowed jumbo frames 207 207
going over your network 208 208
but again, it's slower, 209 209
and it's not necessarily good 210 210
for large network solutions 211 211
that need fast high-quality storage. 212 212
Now, I just mentioned jumbo frames. 213 213
I think this is probably the first time 214 214
we've talked about that. 215 215
Now, by default when you get a frame 216 216
that's going over your Ethernet, 217 217
there is a maximum transmission unit size 218 218
and the default is 1500. 219 219
Now, with a jumbo frame, you're setting things 220 220
that are bigger than 1500 MTUs 221 221
or maximum transmission unit size. 222 222
That's all a jumbo frame means. 223 223
But you have to configure a network 224 224
to support that cause otherwise, by default, 225 225
it's going to drop those jumbo frames. 226 226
Now, one of the new types of storage 227 227
that's covered in this version 228 228
of the Network+ is known as InfiniBand, 229 229
and this is a newer virtualized storage technology. 230 230
It is basically a switched fabric topology 231 231
for high-performance computing. 232 232
The throughput that we're talking about here 233 233
is greater than 600 gigabits per second 234 234
with very, very low latency 235 235
of half a microsecond. 236 236
It is extremely fast. 237 237
It is extremely dedicated. 238 238
And it is extremely expensive. 239 239
Unless you're working at something 240 240
like a cloud computing center 241 241
or a really high-speed data center, 242 242
you're probably not going to be dealing 243 243
with InfiniBand any time soon. 244 244
Now, this is a direct or switch connection 245 245
that goes between the servers 246 246
and the storage systems 247 247
with these specialized plugs 248 248
that you can see here on the screen. 249 249
Now, again, where are you going to find these? 250 250
High-performance computing centers. 251 251
If you're running a very large 252 252
high-capacity processing, 253 253
high-capacity storage solution, 254 254
you may want to look into InfiniBand. 255 255
But for most of us who are working 256 256
at small offices, home offices, 257 257
medium-sized businesses, 258 258
or even Fortune 500 companies, 259 259
you're likely never going 260 260
to run into an InfiniBand solution. 261 261
This is an enterprise class solution 262 262
for really big data centers 263 263
who focus on big data. 264 264
Next, we're going to talk about virtual firewalls and routers. 265 265
So, going back to our first image, 266 266
I have this virtual server 267 267
with six or seven machines on it. 268 268
Now, how am I going to connect 269 269
all these virtual servers together? 270 270
Because I don't have a router or a switch 271 271
and enough plugs to plug everything 272 272
into physical devices. 273 273
Well, I can do it by using physical devices 274 274
if I create enough network cards, 275 275
or a better way is to virtualize those two. 276 276
And to do that, we can fully virtualize our network 277 277
and therefore, we're going to need 278 278
virtual switches, virtual routers, 279 279
and virtual firewalls. 280 280
Now, different manufacturers are offering 281 281
virtualized versions of their most popular devices. 282 282
So, if you're a Cisco fan 283 283
and you like their PIX firewall, 284 284
you can go ahead and buy a virtual PIX firewall. 285 285
If you like Cisco routers, 286 286
you can buy a virtual one 287 287
and they'll send you the software to install 288 288
into your virtual environment. 289 289
Virtualized routers and firewalls 290 290
are going to provide you 291 291
with all of the same features 292 292
as their physical counterpart, 293 293
without all that pesky wiring. 294 294
Now, how do we designate a virtual firewall 295 295
or a router on the diagram? 296 296
We're going to use the exact same symbol 297 297
we would for a firewall or a router 298 298
and instead, we're going to put 299 299
these little dashes around it. 300 300
So, you can see here 301 301
that it is a virtual router 302 302
instead of a physical router 303 303
because of these dashed lines 304 304
instead of solid lines. 305 305
So, in addition to these virtual routers 306 306
and virtual firewalls, 307 307
we also have virtual switches 308 308
because again, we have to overcome that problem 309 309
of all of these virtual servers 310 310
being on one broadcast domain. 311 311
If we have virtual switches, 312 312
we can actually use layer two VLANs and trunking, 313 313
like we learned about in the last section of the course, 314 314
through these virtual switches. 315 315
This also provides us with quality of service 316 316
and security, and as you can see here, 317 317
inside that blue box, 318 318
that is going to be my virtual server. 319 319
In there, I have three virtual servers 320 320
on one physical piece of hardware, 321 321
and I have a virtual switch 322 322
with three different VLANs. 323 323
Then that's connecting over a single network interface 324 324
to a real switch in my real data center, 325 325
and this is going to connect to a real router, 326 326
and then connect out to the real Internet. 327 327
Next, we want to talk about virtual desktops, 328 328
and this is where you can run a desktop 329 329
inside a web browser. 330 330
You can use it from the web, a laptop, 331 331
a tablet, a smartphone, 332 332
and it's really great for people on the go. 333 333
The thing I really love about virtual desktops, 334 334
which we refer to as VDI, 335 335
it's going to be a virtual desktop infrastructure, 336 336
and they are going to be really easy to secure 337 337
and really easy to upgrade because essentially, 338 338
you get a brand-new desktop 339 339
every time you log in. 340 340
Because all that you're doing 341 341
is creating a virtual file on a server. 342 342
You're not having to actually build a new computer. 343 343
So, the machine on your desk now 344 344
just becomes a dumb device built to access 345 345
this VDI environment. 346 346
All of the important stuff 347 347
is actually kept in my server room. 348 348
And you can see here on the screen 349 349
that I'm a user on the go with my tablet, 350 350
and I'm sitting at Starbucks, 351 351
and down here, I can then reach 352 352
through the Internet to the router, 353 353
to the switch, reach into my desktop, 354 354
back up to my server farm, 355 355
and get the data. 356 356
And just as I was sitting at home 357 357
or in the office, or at Starbucks, 358 358
it all looks the same. 359 359
It doesn't matter where I'm sitting. 360 360
I can do all the same features. 361 361
Virtual desktops are really starting 362 362
to take over and they're really useful. 363 363
Now, what are virtual desktops bad for? 364 364
Well, if you have high-performance computing requirements 365 365
like video editing, gaming, or desktop publishing, 366 366
or any of those things that requires 367 367
a lot of graphic and computing power behind it, 368 368
virtual desktops is probably not for you. 369 369
But for the average user 370 370
who is surfing the Internet, 371 371
doing PowerPoint and Word and Excel, 372 372
virtual desktops are phenomenal, 373 373
and they are really, really a great way 374 374
to increase the security 375 375
and lower your total cost of ownership overtime. 376 376
Now, that is the textbook answer what I just gave you, 377 377
that virtual desktops only work well 378 378
for low performance requirements. 379 379
But I will tell you here in 2020, 380 380
that is not true anymore. 381 381
It is true that there are actual 382 382
gaming virtual desktops that you can get into. 383 383
There are editing and video editing ones, as well. 384 384
For instance, in my company, 385 385
we actually have a subscription to shadow.tech, 386 386
which is shadow PC is what it's called. 387 387
You can log in through the cloud 388 388
to this virtual desktop on their servers 389 389
and it provides you full gaming PCs, 390 390
and we actually use them for our video editing 391 391
because they're really powerful. 392 392
And so, for 25 or 30 bucks a month, 393 393
we get access to a really powerful computer 394 394
in the cloud and no matter 395 395
where my video editors are in the world, 396 396
they can log in, access all the information, 397 397
and do what they need. 398 398
But for the exam, when you hear about VDI, 399 399
you want to think about low power desktops 400 400
for your standard Word and PowerPoint and Internet, 401 401
not something like a high-end gaming machine. 402 402
I just wanted to go ahead and clarify that now 403 403
because sometimes, I get students who say, 404 404
but what about Shadow PCs, that's a VDI? 405 405
And yeah, it is, and it's a great VDI 406 406
and it works really, really well. 407 407
But for an enterprise, 408 408
generally you're going to use VDI 409 409
for low performance requirements. 410 410
All right, let's go back 411 411
to your regularly scheduled lesson. 412 412
And lastly, here we want to talk 413 413
about software-defined networking or SDN. 414 414
This is going to provide the administrator 415 415
with an easy-to-use front end 416 416
to configure physical and virtual devices 417 417
throughout your network. 418 418
All of your configurations 419 419
can be automatically done 420 420
by using software-defined networking. 421 421
It is really great and as an administrator, 422 422
you get an overview of your entire network. 423 423
In the old days, before we had SDN, 424 424
if I had three switches like I do all here on the left, 425 425
and I wanted to configure them, 426 426
I would need to go to each 427 427
and every one of those switches, 428 428
either logically or by remoting 429 429
in using secure shell, 430 430
and make my changes. 431 431
Now, with software-defined networking, 432 432
I just go to my software-defined networking controller, 433 433
I make the change once there, 434 434
and it pushes that configuration change 435 435
across the entire network 436 436
and all of my devices. 437 437
It'll reconfigure the access list. 438 438
It'll reconfigure the MAC filtering. 439 439
And all those different things I need 440 440
as part of software-defined networking. 441 441
It changes the routers and the tables 442 442
and all of that stuff, 443 443
all from one centralized console. 444 444
It is really great and it is a great way 445 445
to virtualize your network 446 446
when you're using virtual switches. 447 447
And doing this can really consolidate it 448 448
with your real-world stuff as well 449 449
because SDN doesn't only have to work virtually, 450 450
it can configure those physical devices too. 451 451
And so, it is something 452 452
you really need to take a look at 453 453
as you get up into the networking world.