-: Network Platform Commands. 2 2
In this video, 3 3
we're going to cover the Network Platform Commands 4 4
for the exam that you need to be aware of. 5 5
Now, there are a lot more commands 6 6
than what we're going to cover in this lesson. 7 7
but for the exam, there are three you need to know. 8 8
Now, when I mention the term network platforms, 9 9
I'm talking about things like routers, switches, 10 10
and firewalls. 11 11
And for the exam, 12 12
I want you to know the 'show interface', 'show config', 13 13
and 'show route' commands 14 14
and how we use them in maintaining 15 15
and troubleshooting our networks. 16 16
So, what is a network platform? 17 17
Well, I know this sounds like a really funny term 18 18
that CompTIA uses here. 19 19
And when they refer to a network platform in the objectives, 20 20
what they're really referring to is any router, switch 21 21
or firewall regardless of the brand or manufacturer. 22 22
This is because CompTIA exams 23 23
are considered vendor neutral exams. 24 24
So we're not asking you just about Cisco. 25 25
We could be asking you about a Cisco router, 26 26
a Juniper switch, or a Sidewinder firewall. 27 27
It doesn't really matter. 28 28
They're all considered network platforms. 29 29
Now, each device manufacturer does create 30 30
their own command line interface, 31 31
that's going to be used to configure, monitor 32 32
and troubleshoot their devices. 33 33
But they're all pretty similar in their actual functions 34 34
and commands 35 35
and most of them are based off Cisco 36 36
because they were one of the first, 37 37
really big router and switch companies out there. 38 38
For this lesson, 39 39
we're going to focus on the three clearly outlined 40 40
inside your objectives. 41 41
Those are: 'show interface', 'show config' and 'show route'. 42 42
These three terms are specific to Cisco devices, 43 43
but similar commands exist for other manufacturers 44 44
like Juniper and Sidewinder devices as well. 45 45
For the 'show interface' command, 46 46
you could use 'show interfaces' with an 'S' on it 47 47
on a Juniper device. 48 48
Or 'cf interface', 49 49
which stands for configure interface 50 50
on a Sidewinder firewall. 51 51
It'll give you the same type of thing. 52 52
Now for the 'show config' command on a Cisco device, 53 53
you could use 'show configuration' on a Juniper device 54 54
or 'cf config' on a Sidewinder device. 55 55
Now for the 'show route' command, 56 56
you would still use 'show route' on Juniper devices, 57 57
but you use 'cf route status' on a Sidewinder firewall. 58 58
For the exam though, 59 59
you're only tested on the three I mentioned, 60 60
'show interface', 'show config', and 'show route'. 61 61
So let's take a look at these three specifically 62 62
and what type of information you can get from them. 63 63
First, we have 'show interface'. 64 64
The 'show interface' command 65 65
is going to display the statistics 66 66
for a network interface on the device. 67 67
Now, if you look at this specific interface, 68 68
instead of all of the different interfaces, 69 69
you'd want to enter 'show interface', 70 70
and then use the ethernet interface you want to look at. 71 71
For example, "show interface ethernet 1/1". 72 72
This would display only the statistics for ethernet 1/1, 73 73
that specific interface in port on that switch or router. 74 74
Now, when you use the 'show interface' command, 75 75
you can see if the interface is up or down, 76 76
if the line protocol is up or down 77 77
and some key statistics that'll help you determine 78 78
if there's any network issues. 79 79
First, you should look at whether the internet address 80 80
is a valid address, 81 81
or do you have an IP address that was assigned 82 82
because you had a DHCP issue. 83 83
If you see an IP address, 84 84
that means you need to investigate your DHCP. 85 85
Second, you should look at the bandwidth 86 86
and see if it matches your cable type. 87 87
In this example, 88 88
the bandwidth is set to 10,000 kilobits per second, 89 89
or 10 megabits per second. 90 90
This means the interface thinks 91 91
it's using a CAT 3 cable. 92 92
Now, if this is incorrect 93 93
and you're actually using a CAT 5 or CAT 6 cable, 94 94
that cable may be damaged, 95 95
which is why the device is only reporting 96 96
that it's capable of 10 megabits per second. 97 97
Third, you want to look at your MTU size. 98 98
By default, this is going to be set to 1500 bytes, 99 99
but if you're using a storage area network, 100 100
you might want to use jumbo frames 101 101
and use something as large as up to 9,000 bytes in size. 102 102
This is going to depend on what network you're looking at. 103 103
Also, you should check to see if there's any runs, giants, 104 104
or errors in the statistics, 105 105
as these are all indications of potential problems. 106 106
Finally, you should check for collisions. 107 107
If you're running full duplex on a switch or router, 108 108
there should not be any collisions 109 109
because each switch port is its own collision domain. 110 110
In this example, I see there are 432 collisions, 111 111
which indicates there's an issue on this switch port, 112 112
or maybe somebody is connected to hubs that switch port 113 113
downstream. 114 114
Now next we have the 'show config'. 115 115
Now 'show config' is a command that's used to display 116 116
the current system configuration to your screen. 117 117
When you use the 'show config' command, 118 118
there are no options or arguments. 119 119
It's just going to be entered as 'show config', 120 120
and you'll hit enter. 121 121
Now for the exam, 122 122
you do not need to understand each and every line 123 123
of this configuration. 124 124
If you move into being a network administrator 125 125
and you decide to take your 126 126
Cisco certified network associate certification or CCNA, 127 127
you're going to be expected to know 128 128
each and every line of this. 129 129
But for now, 130 130
you should be able to read through this configuration 131 131
and identify some key areas. 132 132
First, we have the shared secrets 133 133
that are being stored towards the beginning 134 134
of the configuration file, 135 135
as well as some basic items 136 136
that allow us to configure things like our prompt 137 137
and our message of the day. 138 138
Next we get into some system settings, 139 139
such as the system baud rate, 140 140
which is currently set to 9,600 bits per second, 141 141
when I'm communicating over a console port. 142 142
Next, we have some SNMP settings, 143 143
including enabling or disabling some of the traps 144 144
for this device, 145 145
so it can report back to an SNMP manager. 146 146
In this case, they're all disabled. 147 147
Next, we're going to have some IP settings 148 148
such as those two interface I have "sc0" and "sl0". 149 149
You can see the "sc0" is being set up to use 150 150
a class B private IP of 151 151
172.16.25.142. 152 152
And a route was set to allow traffic out the gateway router 153 153
at 172.16.1.201. 154 154
Now next we have our VMPS, 155 155
which is the VLAN Management Policy Server. 156 156
In this case, 157 157
we have it set to a TFTP server at 158 158
1.1.1.1, 159 159
and it is set to enable. 160 160
Next, we have our DNS set up for this device, 161 161
and this is set up to use two DNS servers, 162 162
a primary one at 163 163
198.92.30.32, 164 164
and a backup at 165 165
171.69.2.132. 166 166
Both of these are enabled, 167 167
and our DNS domain is cisco.com 168 168
because this is a sample configuration file 169 169
that was created for use by Cisco. 170 170
Next, we have our TACacs plus configuration, 171 171
including servers, 172 172
the number of invalid attempts allowed 173 173
and the timeout period. 174 174
After that, we have the configuration for an older protocol 175 175
known as IPX. 176 176
And this device is set to allow IPX traffic 177 177
to be bridged into this network. 178 178
Next, we have the VTP settings, 179 179
which are going to allow us to be in server mode. 180 180
Remember VTP is the VLAN Trunking Protocol. 181 181
And this is a proprietary protocol used by Cisco devices 182 182
to exchange VLAN information. 183 183
After that, we have some spanning tree protocol settings 184 184
specifically that we have enabled STP 185 185
leave a max age set at 20. 186 186
After that, we have CGMP, which is set to enable. 187 187
Now, CGMP is not something we've talked about before 188 188
in this course, 189 189
but this is a Cisco specific thing. 190 190
CGMP is the Cisco Group Management Protocol, 191 191
it's an older form of IGP used by Cisco switches. 192 192
Next we have CIS Log. 193 193
And in this case, it's set to enabled for the console 194 194
and it's set to disabled for the server. 195 195
All the logging levels are set here as well 196 196
and you could see they're either two or five, 197 197
anything above those numbers would not be forwarded 198 198
or logged by CIS log. 199 199
Now, after that, we have the NTP section, 200 200
which configures our Network Time Protocol server 201 201
that we're going to use, 202 202
including what time zone we're in 203 203
and if we're going to enable NTP clients or not. 204 204
After that, we have a permit list, 205 205
which is essentially an ACL. 206 206
In this case, the permit list is set to disabled. 207 207
Finally, we have the first module in our device, 208 208
a two port 100 base TX device. 209 209
So this is a fast ethernet device. 210 210
Here, you can see what has been enabled and disabled 211 211
on this particular module or interface. 212 212
As I said, you don't need to be an expert on any of this. 213 213
I just wanted to show you what it looked like 214 214
inside of a configuration file, 215 215
when you use the 'show config' command, 216 216
our third command is ''show route''. 217 217
The 'show route' command is going to be used 218 218
to display the current state of the routing table 219 219
on the device. 220 220
More accurately, we're normally going to enter this command 221 221
as show IP route and hitting enter. 222 222
This is because we normally want to see 223 223
the routes associated with IP based networks, 224 224
for most of our networks. 225 225
Most of us aren't running any networks that aren't IP based. 226 226
For example, you're probably not running an IPX 227 227
or AppleTalk network anymore. 228 228
Now here's an example of a router that I have 229 229
that I've entered show IP route on. 230 230
Here you can see, 231 231
first we have a legend that shows us all the different codes 232 232
and what they mean. 233 233
Then we see the gateway of last resort, 234 234
which is our default gateway that we're going to use, 235 235
if we can't route traffic to any of the other routes 236 236
that are listed below. 237 237
As you look at those routes, 238 238
you can see they're written in three columns. 239 239
The first column indicates 240 240
how the route is going to be derived. 241 241
Is it from IGRP, RIP, OSPF, directly connected, 242 242
a static route, EGP derived, or BGP derived? 243 243
Then we have our second column 244 244
and this tells us the type of route it is, 245 245
when we learn it through OSPF. 246 246
In this example, 247 247
we have three of these types of routes 248 248
and they're listed as E2, for OSPF, 249 249
external type 2 routes. 250 250
Then we have the address of the remote network, 251 251
such as 150.150.0.0. 252 252
And then we see a pair of numbers inside some brackets. 253 253
In this example, it's 160/5. 254 254
This means 160 is the administrative distance 255 255
of the information source 256 256
and five is the metric for this route. 257 257
Next, we see the via and an IP address, 258 258
which is the address of the next router 259 259
to the remote network. 260 260
After that we see a time 261 261
and this is the last time the route was updated. 262 262
It's written in hours, minutes and seconds. 263 263
So this first route is only one minute old. 264 264
Finally, we have the interface use for a specified network 265 265
in this route. 266 266
In this case, ethernet 2 267 267
is designated as the path for sending traffic 268 268
to this particular network. 269 269
So, as you can see from this show IP route command 270 270
that OSPF routes have an administrative distance of 160 271 271
and a metric of only five. 272 272
The EGP routes have an administrative distance of 200 273 273
and a metric of either 128 or 129. 274 274
This tells me that the router trusts the OSPS routes 275 275
more than it trust the EGP routes, right? 276 276
Now this makes sense 277 277
if you think back to our previous discussions 278 278
on broader protocols, 279 279
administrative distances and the believability 280 280
of these metrics. 281 281
All right, let's look one more time at the show IP route, 282 282
but this time on a different router. 283 283
Here, you could see a router that has fewer routes. 284 284
In this router. I only have four routes. 285 285
My default, route of one 60.89.0.0, 286 286
and then three subnets. 287 287
Here, you can see the connected route is showing 288 288
as possibly being down on ethernet zero. 289 289
Next, we see two IGRP derive routes 290 290
and they're using ISIS level 2 as the route type. 291 291
These routes have a lower administrative distance 292 292
than the OSPF an EGP routes that we looked at earlier, 293 293
but their metric is a bit higher than an OSPF one 294 294
that we saw before. 295 295
Now, if you wanted to get additional details 296 296
on any of these specific routes, 297 297
you could enter show IP route 298 298
and the IP address for that network 299 299
to get additional details, 300 300
including its routing metrics, reliability, 301 301
the delay on the network, 302 302
and even the hop count as you can see here. 303 303
So in summary, 304 304
you need to remember that 'show interface' 305 305
gives you the statistics for an interface 306 306
that 'show config' is used to display 307 307
the current configuration on device 308 308
and 'show route' is going to be used to get information 309 309
from the routes learned by a particular network device. 310 310
(upbeat music)