Hey guys, welcome back. So, last video we looked at a way to really track packets
and the packets that are actually being sent to and from this machine individually as
packets, and now we're going to talk about a man called "netstat" which is an
abbreviated term for network statistics. So, basically the command that we're
going to be using throughout this video is netstat, and based on the flags that
we pass it it's going to return different statistics. So, if I put "netstat -nr"
the "n" option makes netstat print addresses as dots, you know dotted IP
addresses rather than symbolic host network name, so this is gonna make sense
if you want to see the actual IP addresses rather than the domains that are
connected to the machine. And, so this is what I've got right now. Basically, gives
us the information that were looking for regarding the IP routing table, and so
the "r" flag in that command that I just put basically states that we're looking
for the kernel IP routing table, and that basically shows what certain things are
routed to. So, let's actually display network interface statistics
themselves, and we're gonna do that with the "-I" command. So, we're gonna take
"netstat -I" and this shows us the usage of each of our devices, and so we can see
the local host here which was configured has sent this many packets right here, and
it's received this many packets. As compared to our wireless interface which
so far has received that many, and actually this is bytes not packets, and
this many. So, you can kind of see how this would be useful.
We can actually display connections to our machine as well, and so I think my system
update is still going, it is, so this is going to be good. What we're gonna do is run the "netstat" with
the flags -ta, and this is going look for active sockets and it's going to print out the
status of them, and basically you know the foreign address in the local address.
So, this obviously is our local machine here. These are the foreign addresses that
it's connecting to, and so what I'm going to do is I'm going to run "netstat -tan"
and it's gonna show IP addresses instead of the host names. And
so you can see how that's gonna be useful because we can actually combine
elements of the different flags that we're passing to the netstat command, and
it's basically you know going to change the way that each of these outputs works.
And, so that is how you would use netstat to view active connections and active
route of IP addresses internally through through the command line here, and you
know if you're not sure if you think your computer may be connecting to
a malicious host or something, what you can do is you can take these IP addresses
and you can actually look them up through through a website like
network-tools.
I think it's network-tools.com it could be .org I'm not sure, but
you can find information about each one of these hosts if you're not sure where
it came from. And, just by looking at these you might be able to you know the
actual host names themselves you may know what they are. I think these
are all my updates that are happening through the software update, or so that's
I don't recognize any of these. So, that's how to use netstat. I hope you guys enjoyed
this video and found informative. I hope you guys can basically understand what
netstat does. It's a very simple command but it's a very useful in a lot of
circumstances. So, thank you guys for watching this video, I'll see you guys
soon.