So, now you don't only have to scan devices on your local network, you can
also scan external IP addresses or host names. So, I'm going to scan my server
here by typing "nmap pointybracket.net" and then the host name of my server.
It's gonna take a moment and I've got a lot of open ports just because I have so many different
things running. I've got, there's a lot of things that run on it and
some things that I just setup that I've never really used and haven't bothered to
shut them down, and so what we get here is my host and we can see that I've got FTP,
SSH, SMTP,
we've got the standard domain in HTTP, pop3,
there's a bunch of stuff here and I'm not going to go into what all those are
but we can see that these are everything that the server has. You can also
set a file, so let me clear this. Let's open up gedit.
So, we're going to create a file of of hosts that we want to regularly scan and
this can save time when we scan them if you've got like you know a few hosts
that you regularly check on. So, I'm going to put "pointybracket.net" "192.168.0.1"
and "192.168.0.100" and I'm gonna save this as "networks.txt"
So, what we can do there is we can type "nmap -iL -/networks.txt."
so it's a lowercase "i" and a capital "L"
and then the location of that file, so it was "networks.txt" in my home directory.
This is going to scan each of the hosts that is in that networks file.
It returns in the order that they were scanned in, so that's pretty neat. I want
to go over a few more things with you guys regarding this command it does get
pretty big there's so much so that you can do with this, and so I really urge
you guys to go and explore this if networking is one of your interests, if
you want to really you know follow that. One of the things I want to show you
guys is how we can turn on OS inversion detection during the scan, and so what
we're going to do is type "nmap -A 192.168.0-100" and this is going
to scan, oh I had a little typo in the IP address there so I had just fix that,
so this should tell me the operating system versions that are running on the
devices on my network, and you can also find this information about other hosts.
Aside from this, just while this is running you can scan aa network and
find out which servers and devices are up and running by using the flag
"-sP" You can display the reason that a port is in a
particular state by having the flag "--reason" You can choose to
only show opened ports which appears to be the default functionality here, it
doesn't show the closed ports. You can actually also show all of the host
interfaces for a machine by typing "--iflist" in the list of arguments for this
command, and I mean again it's really big so go ahead and look this up.
If you wanna type in google.com "nmap commands" there's a bunch of
different ones that you guys should play around with,
this was more of an introduction onto the most common or basic functionalities of
this program. I'm going to cancel this here and I'm just going to restart. This will go a bit
faster, I'm just going to target my own IP address here so we can get this done and
you guys can see the example output that this is gonna do when adding the "-A"
slag in here. So, here you can see a lot of information about this machine. Let's go to the
top here. We've got the port, the state, and the service, as well as the version of
the service. So, I have Apache 2.4.12 installed and that's also
the same one here.
If we go down we get more information about the host cell, so we have OS UNIX, we've got
the computer name, the domain name if anything is configured, the fully
qualified domain name, and just a lot more information. So, that is the nmap
command and it would be useful if you're trying to just scan your network, and one
of the examples that comes off the top of my head that would be you know when
I would use command is if I noticed that the internets you know
running a bit slow. Let's say I've got 10 people in my house and half of them may or may
not be using the internet and I wanna see how many people are online,
this is what I would do in that instance or if you you know if you want to check
how many machines offer a certain service, or what the IP address is that
you need to use to access a certain service on another machine, this would help you figure
that out.
So, thank you guys for watching this video, I will see you guys again soon.