Darren New wrote:
> Invisible wrote:
>> IP is different. It's designed to work for large networks.
> 
> And SONET and ATM and X.25 and ISDN aren't?  Do you even know what those 
> networks are?

Last time I checked, ISDN is point-to-point only (i.e., the smallest 
possible kind of network). I was under the impression that ATM is as 
well, but I haven't actually used ATM.

> Here's a hint: When you phone America from the UK, your voice is not 
> traveling over IP.  Heck, the busy signal isn't traveling over IP either.

I try to avoid phoning America. It's almost impossible to hear what the 
other person is saying. (Why this would be the case in a digital system 
is beyond me...)

>> Sure, you don't usually talk to them directly; usually you use one of 
>> the IP addresses from the block assigned to your ISP.
> 
> Ding ding! Guess what? They aren't assigned centrally. Your ISP assined 
> you yours, mine assigned me mine.

And where does the ISP get their IP block from?

Yeah, exactly: They're assigned centrally.

>> But my point is,
>> you can't just pick a random number out of the air and try to use that 
>> as your IP address. It won't work.
> 
> That's a different statement from "they're assigned centrally."
> 
> And yes, actually, you can. You'll break other people, but it'll work if 
> you do it right.

If I just pick an IP address at random, it won't even route correctly.

Oh, sure, if I'm building a *private* network not connected to anything 
else, I can use whatever addresses I want. (Hell, I don't even have to 
use IP.) But then everybody on *that* network needs centrally-assigned 
addresses...

-- 
http://blog.orphi.me.uk/
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