So now that we've let our management system install and run for a little bit
to discover all of the various devices on our network,
we're going to take a few moments and configure a network management system to
actually gather useful information from all of these devices.
Now obviously, every network management system configures differently,
but the basics are the same where you go into the device and
you set it up and you tell it what interfaces to monitor and
look at the reports on it.
So we're going to do that here with our PRTG installation.
So first, let's take a look at what the system discovered about our network.
So there is the local probe, which is the device the probe is running on,
it found a Linux Mac OS UNIX device, which is our UNIX server,
and there are a couple of unknown devices as well.
There is 192.168 .150 .7 and there is a .133,
which honestly, I don't know what that is,
it's not anything I set up.
It's probably something within the Azure infrastructure.
And then of course, it discovered itself, which is the .5.
Now you'll notice that it did not actually find the .4 address,
which is our Globomantics Windows Server.
I can almost guarantee you that's because the
Windows firewall prevented the pings,
and the way these network probes work generally,
is it will do a ping scan of everything on the network,
and if it discovers a device that responds to ping,
then it will attempt to discover what services are running on it.
That's how it discovered the SSL certificate issues and the
RDP session that's on this .133 and HTTP,
etc.
So before we can actually put our main file and print server,
globosrv1, into the network management system,
we need to check the firewall and make sure that it allows ICMP and
SNMP traffic at least from the management server.
So let's jump over to our main file server and do exactly that.
So we'll check the Windows firewall, it is enabled,
and a lot of organizations, some that I've worked at,
has just a policy that they just go turn off the Windows firewall,
and while that might be somewhat useful on a smaller network,
as you get larger,
you probably want to have that little bit of added protection there and
control what traffic goes between each of your servers,
that's just my opinion though.
That opinion and 5.50 will get you a cup of coffee at a national coffee chain.
So if we go in here and we look at the inbound firewall rules,
first thing we'll do is we'll check that SNMP is open.
So we scroll down here to the Ss and we see that the SNMP service for UDP
In is enabled for both domain and private and public.
So SNMP works, but we don't see any ping or ICMP,
so let's go ahead and create a new rule that allows ICMP from our local network.
Now since this is a custom rule,
we will go ahead and choose custom because we are not allowing TCP or UDP.
We're allowing ICMP, which is its own protocol.
So let's move this up a little bit, hit Next,
we're going to say it applies to all programs,
go ahead and hit Next, and we're going to choose the protocol type of ICMPv4.
You'll notice that everything else is grayed out because there's not
really the concept of protocol numbers or ports with ICMP,
but we can still customize the type of ICMP requests that we respond to.
Now if we wanted to lock this down even further,
we could say we only want to respond to echo request,
which is what an ICMP packet is, but we'll go ahead and say all ICMP packets,
we'll hit Next, and it applies to any of the local IP addresses,
and we could leave it as any IP address,
but let's just go ahead and add our local subnet,
so 192.168 .150 .0 /24, we'll hit OK, we'll hit Next,
we're going to allow the connection, obviously,
it's valid for domain, private, and public,
and we're going to name this one ICMPv4 Allow,
and hit Finish, and there is our new rule,
ICMPv4 Allow.
So let's see if that fixed our ping problem.
We'll go out here, ping that, and now we can actually ping our server.
Now if we were to let the network discovery run again,
it would discover this server now because it can ping it,
but since we don't have the proper SNMP community strings
in our network management platform,
you still won't be able to do any kind of management with it.
So now we verified that the Windows firewall will allow
us to actually manage these devices, let's move on to actually configuring them in our network management system.