So now we move onto the demo.
Well, we're quite simply going to examine devices with SNMP,
and to do that,
we're going to use an SNMP walker or a MIB explorer on our Windows box.
So we're going to use the managed engine and MIB browser,
which is freely available for download.
It is a Java-based application, of course, like so many of them are.
And to start off with,
we are going to look at the localhost or the system
this MIB browser is running on.
Now obviously, we know it's a Windows box,
but we can find out more information about the box if we go to say
the SNMP v2 MIB and we browse down to internet,
mgmt, mib-2, system, and we can get the system description and things like that.
So we'll get the system description, in this case,
it comes up as an Intel64 Family 6 Model 45 Stepping 7.
I'm sure that means something to some of you hardware people out there.
But we see the Windows version is 6.3.
We can look up the sysObjectID, in this case,
it is the ID that represents where in the MIB tree you can
get specific information about this guy,
and in this case, it's in a MIB we don't have loaded,
so we don't get the translation of that OID,
we just get the dot notation after enterprises,
311 happens to Microsoft.
We can get the system up time, yep, 5 days, 11 hours, 0 minutes, 38 seconds.
And you'll see down below, you actually get the full OID that you're looking at.
It tells you the syntax and the access we have and the description that recall
from that MIB file that we looked at earlier in the module.
This is the description that comes across from that MIB file.
So that's what it looks like when you get a single value MIB.
What if you need to gather information from the system where you have
multiple of the same devices like network cards,
for example.
Even though, in this virtual machine,
I only have one physical air quotes network card,
if we look at SNMP,
we see that Windows exposes a lot of virtual network cards or
virtual drive information to the SNMP stack.
So to get to that information, we can drill into the interface MIB like so,
I'll spread this over just a little bit so that we can see internet,
mgmt, mib-2, interfaces, and we can get the ifTable.
Now this is a table MIB so there is more than one value in it.
We'll click the little icon up here to view the table data
and we'll hit Start and there are all of the network cards
in this particular server.
SNMP reports 23 of them.
And you see we've got things like the loopback interface and WAN
miniports for all the different types of drivers.
We have the AnyConnect secure mobility client virtual adapter because I
have the AnyConnect client installed on this server.
I've got the WAN miniport adapters, etc installed on here.
However, for most cases, we're going to be interested in this guy right here,
number 12, the Intel 82574L Gigabit Network Connection because honestly,
that's the only one that's actually going to report back any
statistics as we'll see here in a moment.
You'll remember that interface index number 12 that will play into
the next section of the MIB walking that we do.
So if we close the table and we expand the ifTable and the ifEntry,
for every entry in that table, we can get this information,
the description, the type, the Mtu, the physical address,
you can read all of the information that's there.
You can get very detailed specific information for
devices that expose that information, such as Cisco routers and switches,
and to a lesser extent, Windows servers.
So what happens if we go down and get one of these
pieces of information like ifnOctets,
so we'll click on this guy and we'll say to get and you'll notice that
there is the interface and octets for all 23 interfaces,
of course, most of them are zeros.
The only one we're really interested in,
of course, is in ifnOctets.12, which is the Intel ethernet adapter.
Now of course,
we can get more than just interface information out of SNMP devices.
If we load up the Cisco MIB and we look at a Cisco device,
so we'll drill into this guy and we will look at the local system,
and that gives us all kinds of information here.
So we'll double-click romid and tell it to get this guy,
and we'll see that there is the version of iOS this particular guy is running.
We can ask it for the amount of free memory.
In this case, it has that number of bytes of free memory.
If we scroll down further in the MIB, we can actually ask it for CPU information.
So if we scroll down a little bit more, we can get the avgBusy1,
which is the 1 minute exponentially-decayed moving
average of the CPU busy percentage, in this case,
it's 5%, and if we get the avgBusy5, we see it's 6%,
so this router is kind of bored to be honest.
And so, you can see with the proper SNMP management tool,
such as the one we'll install later in this course, you affect great management and great information on your network's devices.