IP Security and Network Utility

Hey guys, this is Matad 101. This is just going to be a video on something called Network Utility. If you just go into Spotlight and look up Network Utility, um, you will see, um, this thing. It's called Network Utility; it's in your Utilities folder by default.

Um, it will show you, um, information about your, um, network: um, hardware address, it's your MAC address, I think, or your IP address, your link speed, um, your link status, vendor, I don't care, sent packets—that's all the packets of information you've sent out and received, send errors—no errors. Great! Netstat, you can just see, um, the information about your computer and what ports are open and such. Um, that's kind of useless; um, well, it's useful technically.

You can also ping a website or an IP address just to see if it's up. Like, I'll ping myself and it'll work; presumably, okay, that's not working because I'm on stealth mode, but I can ping Google and it'll respond. There, it says responding. So, you can also look up like google.com, okay? And it'll show you a little bit of information.

Traceroute just says all the IP addresses you go through to get to Google. So, first, it says the IP address of the router, how fast it got there, and then it'll say, um, the next place you go. And WHOIS, you can look up any website like google.com, and it'll show you all the info about them. Um, and it'll show you like there are a bunch of different ones, so I'll just type full address. There are a bunch of Googles because other people have tried to fake that.

You can also type an email address here, but that's dumb. And for port scan, of course, you can check all the open ports on your machine. Like, I have Port FTP open; I have SSH open; I have HTTP open; I do have 592 open, um, because I am available to VNC. Except my password is long, and you cannot VNC to my remote IP address.

Which brings me to another topic that I'll also be discussing in this video. Um, people seem to think that every computer has an IP address. This is true and false. On your network, if you're on the same network as someone, you can know their local IP; that's normally 192.168 something.something. Normally, it's 1.12.1, and if your internet's a little weird or your router is weird, it'll be something other than that.

People also think that if your friend is sitting on their computer at home, that their computer has an IP address. That's probably not true. I can almost practically say 99% of all houses are set this way. When you have a router, wireless or not, um, or any kind of internet connection like that, your whole network has um... So anyone with the wireless network who connects to their wireless network, their internet connection has one IP address.

So if you have Comcast internet, and your router's hooked up to some Comcast internet check, and it's projecting to all your computers, you only have one IP address, and that's your Comcast IP address. So, how could anyone possibly SSH to your remote IP address or VNC to your remote IP address and monitor your screen if there are multiple computers on your IP address?

How would the machine who's VNCing even know which computer to connect to? So basically, the firewall is built into any browser or, um, router, I mean, and the firewall basically determines what ports, and VNC is Port 59 for instance, what ports go to what machines.

By default, your router um, doesn't let any ports open unless you have some funky router. I do have Port 22 open to my Ubuntu Linux machine because I like being able to SSH to it from the road, but, um, I still have powerful passwords, and any packets I receive that aren't perfect, that are corrupted anyway, will just be thrown away.

I don't think you'll find a glitch in my router; I really don't. But, um, anyway, so even if someone knows your remote IP, it's not that much of a risk, I can assure you. I don't even think you'd respond to a ping, so I wouldn't be worried about anyone finding your remote IP address and controlling your screen.

Because your router wouldn't know which computer to connect it to. Now, if you have one Comcast box, that Comcast, the wires fo...