In this video,
we're going to cover the network platform commands
for the exam that you need to be aware of.
Now, when I mention the term network platforms,
I'm talking about things like routers, switches,
and firewalls.
And for the exam,
I want you to know the show interface, show config,
and show route commands
and how we use them in maintaining
and troubleshooting our networks.
So what is a network platform?
Well, I know this sounds like a really funny term
that CompTIA uses here,
but when they refer to a network platform
and the objectives,
what they're really referring to is any router,
switch, or firewall,
regardless of the brand or manufacturer.
This is because CompTIA exams
are considered vendor neutral exams.
So we're not asking you just about Cisco.
We could be asking about a Cisco router, a Juniper switch,
or a Sidewinder firewall.
It doesn't really matter.
They're all considered network platforms.
Now, each device manufacturer
does create their own command line interface
that's going to be used to configure, monitor,
and troubleshoot their devices,
but they're all pretty similar
in their actual functions and commands,
and most of them are based off Cisco
because they were one of the first really big
router and switch companies out there.
For this lesson, we're going to focus on show interface,
show config, and show route.
These three terms are specific to Cisco devices,
but similar commands exist
for other manufacturers like Juniper
and Sidewinder devices as well.
For the show interface command,
you could use show interfaces with an S on it,
on a Juniper device or CF interface,
which stands for "configure interface"
on a Sidewinder firewall.
It'll give you the same type of thing.
Now for the show config command on a Cisco device,
you could use show configuration on a Juniper device
or CF config on a Sidewinder device.
Now for the show route command,
you would still use show route on Juniper devices,
but you'd use CF route status on a Sidewinder firewall.
So let's take a look at these three specifically
show interface, show config, and show route,
and what type of information you can get from them.
First, we have show interface.
The show interface command is going to display the statistics
for a network interface on the device.
Now, if you look at the specific interface,
instead of all of the different interfaces
you'd want to enter show interface
and then use the ethernet interface you want to look at.
For example, show interface ethernet 1/1.
This would display only the statistics for ethernet 1/1,
that specific interface and port on that switcher router.
Now, when you use the show interface command,
you can see if the interface is up or down,
if the line protocol is up or down,
in some key statistics that'll help you determine
if there's any network issues.
First, you should look at whether the internet address
is a valid address
or do you have an APIPA address that was assigned
because you had a DHCP issue.
If you see an APIPA address,
that means you need to investigate your DHCP.
Second, you should look at the bandwidth
and see if it matches your cable type.
In this example, the bandwidth is set
to 10,000 kilobits per second or 10 megabits per second.
This means the interface
thinks it's using a Cat 3 cable.
Now, if this is incorrect
and you're actually using a Cat 5 or a Cat 6 cable,
that cable may be damaged,
which is why the device is only reporting
that it's capable of 10 megabits per second.
Third, you want to look at your MTU size.
By default, this is going to be set to 1500 bytes,
but if you're using a storage area network,
you might want to use jumbo frames
and use something as large as up to 9,000 bytes in size.
This is going to depend on what network you're looking at.
Also, you should check to see if there's any runts, giants,
or errors in the statistics,
as these are all indications of potential problems.
Finally, you should check for collisions.
If you're running full duplex on a switch or router,
there should not be any collisions
because each switch port is its own collision domain.
In this example, I see there are 432 collisions,
which indicates there's an issue on this switch port,
or maybe somebody's connected
a hub to that switch port downstream.
Now, next we have the show config.
Now, show config is a command
that's used to display the current system configuration
to your screen.
When you use the show config command,
there are no options or arguments.
It's just going to be entered
as show config and you'll hit enter.
Now for the exam, you do not need to understand
each and every line of this configuration.
If you move into being a network administrator
and you decide to take your
Cisco Certified Network Associate Certification or CCNA,
you're going to be expected to know
each and every line of this.
But for now, you should be able to read
through this configuration and identify some key areas.
First, we have the shared secrets
that are being stored towards
the beginning of the configuration file,
as well as some basic items that allow us
to configure things like our prompt
and our message of the day.
Next, we get into some system settings
such as the system baud rate,
which is currently set to 9,600 bits per second
when I'm communicating over a console port.
Next, we have some SNMP settings including enabling
or disabling some of the traps for this device
so it can report back to an SNMP manager.
In this case, they're all disabled.
Next, we're going to have some IP settings
such as those two interfaces I have:
sc0
and sl0.
You can see that sc0 is being set up
to use a Class B private IP
of 172.16.25.142,
and a route was set to allow traffic out the gateway router
at 172.16.10.201.
Now, next, we have our VMPS,
which is the VLAN Management Policy Server.
In this case, we have it set to a TFTP server at 1.1.1.1,
and it is set to enable.
Next, we have our DNS set up for this device,
and this is set up to use two DNS servers,
a primary one at 198.92.30.32,
and a backup at 171.69.2.132.
Both of these are enabled and our DNS domain is cisco.com
because this is a sample configuration file
that was created for use by Cisco.
Next, we have our TACACS+ configuration,
including its servers,
the number of invalid attempts allowed,
and the timeout period.
After that, we have the configuration
for an older protocol known as IPX,
and this device is set to allow IPX traffic
to be bridged into this network.
Next, we have the VTP settings,
which are going to allow us to be in server mode.
Remember, VTP is the VLAN trunking protocol,
and this is a proprietary protocol used by Cisco devices
to exchange VLAN information.
After that, we have some spanning tree protocol settings,
specifically, that we've enabled STP
and we have a max age set at 20.
After that, we have CGMP, which is set to enable.
Now, CGMP is not something
we've talked about before in this course,
but this is a Cisco specific thing.
CGMP is the Cisco Group Management Protocol;
It's an older form of IGMP used by Cisco switches.
Next we have syslog,
and in this case, it's set to enable for the console
and it's set to disabled for the server.
All the logging levels are set here as well,
and you can see they're either 2 or 5.
Anything above those numbers would not be forwarded
or logged by Syslog.
Now, after that, we have the NTP section,
which configures our network time protocol server
that we're going to use,
including what time zone we're in
and if we're going to enable NTP clients or not.
After that, we have a permit list,
which is essentially an ACL.
In this case, the permit list is set to disable.
Finally, we have the first module in our device,
a 2-port 100BaseTX device,
so this is a fast ethernet device.
Here you could see what has been enabled and disabled
on this particular module or interface.
As I said, you don't need to be an expert on any of this.
I just wanted to show you what it looked like
inside of a configuration file
when you use the show config command.
Our third command is show route.
The show route command is going to be used to display
the current state of the routing table on the device.
More accurately, we're normally going to enter this command
as show IP route and hitting enter.
This is because we normally want to see the routes
associated with IP based networks
for most of our networks.
Most of us aren't running any networks that aren't IP based.
For example, you're probably not running an IPX
or AppleTalk network anymore.
Now, here's an example of a router that I have
that I've entered show IP route on.
Here you can see first we have a legend
that shows us all the different codes and what they mean.
Then we see the gateway of last resort,
which is our default gateway
that we're going to use if we can't route traffic
to any of the other routes that are listed below.
As you look at those routes,
you can see they're written in three columns.
The first column indicates
how the route is going to be derived.
Is it from IGRP, RIP, OSPF, directly connected,
a static route, EGP derived, or BGP derived.
Then we have our second column,
and this tells us the type of route it is
when we learn it through OSPF.
In this example, we have three of these type of routes,
and they're listed as E2 for OSPF external type two routes.
Then we have the address of the remote network
such as 150.150.0.0,
and then we see a pair numbers inside some brackets.
In this example, it's one 60/five.
This means 160 is the administrative distance
of the information source,
and five is the metric for this route.
Next, we see the via and an IP address,
which is the address of the next router
to the remote network.
After that, we see a time,
and this is the last time the route was updated.
It's written in hours, minutes, and seconds,
so this first route is only one minute old.
Finally, we have the interface used
for a specified network in this route.
In this case, Ethernet2 is designated as the path
for sending traffic to this particular network.
So as you can see from the show IP route command
that OSPF routes have an administrative distance of 160
and a metric of only 5.
The EGP routes have an administrative distance of 200
and a metric of either 128 or 129.
This tells me that the router trust the OSPF routes
more than a trust the EGP routes, right?
Now, this makes sense if you think back
to our previous discussions on router protocols,
administrative distances,
and the believability of these metrics.
All right, let's look one more time at the show IP route,
but this time on a different router.
Here you can see a router that has fewer routes.
In this router, I only have four routes.
My default route of 160.89.0.0
and then three subnets.
Here you can see the connected route
is showing it's possibly being down on Ethernet0.
Next, we see two IGRP derived routes,
and they're using I as level 2 as their route type.
These routes have a lower administrative distance
than the OSPF and EGP routes that we looked at earlier,
but their metric is a bit higher than an OSPF one
that we saw before.
Now if you wanted to get additional details
on any of these specific routes,
you could enter show IP route
and the IP address for that network
to get additional details, including its routing metrics,
reliability, the delay on the network,
and even the hop count, as you can see here.
So in summary, you need to remember
that show interface gives you the statistics
for an interface,
that show config is used to display
the current configuration device,
and show route is going to be used
to get information from the routes learned
by a particular network device.