hpr-knowledge-base/hpr_transcripts/hpr0091.txt

Episode: 91
Title: HPR0091: Hosts File
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr0091/hpr0091.mp3
Transcribed: 2025-10-07 11:23:09

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Outro Music
Welcome to this episode of Hacker Public Radio, this is Zokien and I'll be your host
for today.
I'm going to be talking about the host's file, but before I can do that, I've got to
explain a little bit about DNS and the internet and how it works roughly.
Every computer has been given a unique number or IP address.
Think of this as a phone number.
For the purposes of this analogy, imagine that you always have to enter the area code.
Now to get to another computer you need a CypHS or phone number, otherwise you can't
talk to it.
I mean, if you've got the phone, you need to know the phone number because otherwise
you don't dial it.
Now what you can do is phone the yellow pages up and ask to be put through to someone.
So there is this yellow pages containing everyone's name and number.
If you want to phone Google, you just look them up in the yellow pages.
However, instead of this being your local yellow pages because the numbers change too
quickly for that to work, you can actually phone another number up first for the operator
if you will.
And they will give you the phone number for Google.
Now in actuality, you don't need to use the yellow pages because the computer does this
for you.
You type in google.com and it looks up the phone number and dials it.
You can put the phone number in direct vote for a quick demonstration.
If you open up a command line or terminal in Windows, the Windows key and R should bring
up a run program dialog if not start run.
You can enter CMD if you're on Vista or XP in 2000.
I think it is or command if you're on 95 and 98.
Click OK and it will open up the terminal and in Linux, it depends on the Windows manager
and distro and whatever you're on.
I'm sure you probably know how to do that just open up a terminal or be under there somewhere.
So in the Windows, it's just open up.
You have to have a ping, it's P-I-N-G, Papa, India, November, Gulf, then it's space www.google.com
and press Enter and it will run something and tell you something back, something like
ping www.google.com, open brackets 208.67.219.231, close brackets and then a certain amount
of data, bytes of data and percentage that it worked and didn't work.
If you're on Linux, it will probably keep running forever so you need to control C out
of this.
Now the number there 208.67.219.231 is the phone number of Google.
Well, one of the phone numbers.
They have lots of people phoning, so they have several phone numbers.
But you open up the web browser and Firefox or whatever you use and enter 208.67.219.231
or whatever number you just found out in the address bar and hit Enter and hey, press
don't, it loads Google app.
You type the number into the computer, you don't have to look it up.
You can do this with any page you want, in fact.
But what's the point because phone numbers change, it's all dynamic.
You can pay for static IP addresses but it's normally much more expensive.
So people use like dns.com and software if they want to do stuff like that, but there's
no real point.
Your IP address is changed, so there's no point as you remember that, you just remember
Google.
That's the whole point of it.
It's designed to be human readable, Google.com is a lot easier to remember than 208.67.
Whatever the number was, see you've forgotten already, 208.67.219.231.
I've got it written in front of me that's the only reason I know.
Google.com, everyone can remember that.
So the whole dns thing is basically a yellow page is looking up computer rest of the phone
numbers for them.
This is a huge simplification if you actually know a lot more about dns and want to talk
about it, feel free to do your own hack public radio episode.
But that's basically enough for my purposes to explain the hosts file here.
The host file is a bit like a piece of paper you have next to the phone, where you write
phone numbers down.
Now you can write any phone number you want, you can write the wrong phone number.
This becomes important in a moment.
When you try and go to a website, instead of phoning yellow pages, you look up on the
bit of paper first.
You look up on the host file.
Once we're talking about yellow pages actually, let's talk about other people's frameworks.
There are several copies of the dns records around this, like one master copy, but it's spread
out to, I think it's five other master servers around, I think it's five anyway.
But there is a certain number of master records around on the internet.
If you actually took these out, the internet would pretty much die, but that's another story.
There are the master ones, but there are also local copies, which the ISPs normally hit
their own copies, so whichever ISPs you use, they have their own copy.
If you go into the network settings, you will be able to see that there will be a dns settings,
a dns server, one dns server, two dns server, three and so on.
That'll be your local ISPs.
You can use other ones, one common one, for example, is open dns, which I will link to
in the show notes.
They have several choices of phone books you can use, in fact, they have a child phone
click one.
For example, you can set up on your kid's machine, it went in and go to any porn sites.
I know.
Depressing.
Stopping porn off the internet.
They also do other things.
They block sites that they think are spammers, for example, that lots of people complain
about.
So you can stop the machine getting hacked, which is pretty cool, and I do actually use
open dns myself.
I didn't set it up on my machine, though, I got my machine to point to the router, or
router, if you're American.
So my computer, the wireless computer, connects to the router.
The router that looks up on the open dns servers to find out where it's meant to be going.
This is quite cool, because then all you need to do is change the router.
You don't need to faff around doing other things, and it can cache copies of it, so you
don't need to keep looking at the phone numbers and stuff.
So that's pretty cool.
Anyway, back to the hosts file.
It will be located in first places.
If you're on the Mac, it's private, etc. hosts apparently.
At least that's what Google told me.
On Windows, it's C kind of backslash, Windows backslash, system 32 backslash, drivers backslash,
etc. backslash hosts.
On Linux, it's simply slash, etc. slash hosts.
Need to mention the Windows file here.
They do have a file, hosts.sam, which stands for sample.
If you put anything in there, it doesn't do anything, which I found out when I first
started playing around with this.
You need to rename it to hosts, just plain hosts.
If you use notepad, gotta be careful, because it will try and put hosts.text.
The Linux file does exist and does already contain stuff, and it's quite important, because
if you overwrite the file, which I did on the friends computer, it killed Sude.
And it couldn't run, and half the stuff didn't work, because it uses the local IP address
it seems.
So gotta be very careful about that, and I ended up having to grab a live CD to fix it.
Once you've done changes, you can reboot to fix it.
Or in Linux, you should be able to do a kill all the dash, hub, iNet, D to restart it.
And those are probably the way, but it caches it.
I found generally so reboot the easiest way, just to make sure everything's flushed.
And there's an example hosts file at www.nvps.org-winhelp-2002-host.com.
I will put that in the show notes.
The basic format though, is you put the IP address and then the URL, for example, if you
want to connect to your local machine, let's say you're running a scroll mail or something
you want to connect to your own machine, you can put 127.0, 0.0.1, which is your local
machine, space, mail.
And then you type in mail in your address bar, and your browser, and it will take you
to your local machine.
Pretty cool.
I've got a setup for the DSL and the router, for example, mainly just some lazy.
And I had some issues originally, I kept changing the IP address and could never remember
them.
So I've got a setup, so I'm just type DSL or router, and it shows me where it is.
So this is the cool thing.
Using the wrong phone number, double-click.net, suck.
They have ads on about the entire internet, it seems.
There's also issues that my space, for example, served ads up from, may not have been double-click,
but it was one of these, and the server got hacked, the ad server got hacked.
Then all you need to do is load my space, suddenly your machine's hacked by this ad.
My space itself was secure, but the ad server wasn't.
And there are a bunch of 12-year-olds that got hacked on this.
Which is really bad.
So what you can do is if you don't want to see a double-click ad ever again, you add
a new life for 1-27.0.0.0.1, space, double-click.net.
So you're saying double-click.net is on my local machine.
So what then happens is you go to a website, there's a double-click ad there.
It says, oh, double-click.
I need to go there.
This in the host file, oh, it's on the local machine, looks on the local machine, can't
find it, gives you a 404 error for it.
However, the rest of the web page loads up because that's different address, and you
may end up with a small iframe saying 404 error or a blank or whatever, but you will
not get the ad.
This is really cool.
It says you're bandwidth as well, and I highly recommend it for most sites.
If you like the sites, if you like the sites, you want them to have money from the ads.
Basically, if it's a project that you like, don't do this, but if it's something big
like my space and they're being idiots, feel free to do it.
Oh, let you figure out the morality of what you feel is right for that or not.
Personally, I'll be tempted to just say block all the ads and just give donations to the
people you like, because then it saves them anyway.
But this is a really cool web blocking ads.
Now, I used to do this a lot, and I said this is MVPS website that they have a copy of
one that blocks pretty much all the sites, and all the really bad dodgy ones and spammers
and stuff.
It blocks a ton of websites that you don't want to go to, and it's really cool.
I've moved on to Privacy, though, from there, and I now is using Squid as a proxy server,
and I'm using that for a lot more because I'm getting it to control my cookies and things
as well as blocking the ads out.
But that's really cool, and I highly recommend it.
That's all I'm going to say for now.
A nice short episode, again, I try not to make these too long.
Sometimes if you end up with a four-hour show, it's just a bit, but ignoring the fact
it's a huge download, it's just way too long to listen to, so I try and keep these sort
of 10, 15 minutes long, just a little bit of information.
Just because after about 20 minutes of brain starts seizing up and you forget things and
you stop listening properly, so let's just try and keep these nice and brief.
I'd like to give a shout out to everyone in the RC chat rooms that talked to me, everyone
that's giving me feedback.
Everyone says, thank you.
This has been Soak.
If you want to talk to me, my website is Soak.org.
All the details on the Hack Public Radio website, you can go in the correspondence and find
me there.
Keep giving me the feedback.
Hopefully, this one will be stereo.
Apparently, the last one was in mono, so I apologize for that.
Thank you very much for listening, and we'll catch you later.
Thank you for listening to Hack with OverGradio.
HPR is sponsored by Carol.net, so head on over to C-A-R-O-DOT-E-T for all of us in the