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?

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.

>> No. But over a fairly short time, that would have sorted itself out.
> Oh yeah? You recon??

Just like pretty much every other group of competing networking technologies.

> 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.

 > 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.

-- 
Darren New, San Diego CA, USA (PST)
    Ada - the programming language trying to avoid
    you literally shooting yourself in the foot.

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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/
http://www.zazzle.com/MathematicalOrchid*

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Mike Raiford wrote:

> Your Kaypro had a reset switch? Ours only had a power switch.

The Dell PCs I have at work don't even have a power switch.

If one of them crashes, you have to unplug it from the wall to turn it 
off...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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Orchid XP v8 wrote:
> Last time I checked, ISDN is point-to-point only

So is TCP.  It's connection-oriented, except for the D-channel, which is 
datagram oriented.

> (i.e., the smallest possible kind of network). 

Yet, oddly enough, orders of magnitude bigger than IP.

> I was under the impression that ATM is as 
> well, but I haven't actually used ATM.

Tell me what you mean by "point to point" if you think IP isn't.

>>> 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.

Nope. They're assigned heirarchically. That's completely different.

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

Of course you have to adjust the routing.

-- 
Darren New, San Diego CA, USA (PST)
    Ada - the programming language trying to avoid
    you literally shooting yourself in the foot.

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On Fri, 14 May 2010 12:38:52 -0700, Darren New wrote:

> Tell me what you mean by "point to point" if you think IP isn't.

Arguably, IP multicast (or broadcast for that matter) isn't point-to-
point.

Jim

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Jim Henderson wrote:
> Arguably, IP multicast (or broadcast for that matter) isn't point-to-
> point.

Except that only works on a LAN. Otherwise, it's the routers duplicating the 
packets to every output. I.e., the same as conference calling.

-- 
Darren New, San Diego CA, USA (PST)
    Ada - the programming language trying to avoid
    you literally shooting yourself in the foot.

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On Fri, 14 May 2010 13:10:32 -0700, Darren New wrote:

> Jim Henderson wrote:
>> Arguably, IP multicast (or broadcast for that matter) isn't point-to-
>> point.
> 
> Except that only works on a LAN. Otherwise, it's the routers duplicating
> the packets to every output. I.e., the same as conference calling.

Depends on how the router implements forwarding for multicast - ISTR that 
some routers can be configured to forward multicast traffic up to a 
specified TTL, but what's forwarded is still multicast traffic.

Jim

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On 5/14/2010 1:12 AM, Invisible wrote:
>> Yes. Who served the IP address to your machine? Time Warner San Diego?
>> I doubt it.
>
> AFAIK, IP addresses are assigned by a central allocation agency.
>
> Sure, you don't usually talk to them directly; usually you use one of
> the IP addresses from the block assigned to your ISP. 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.
Mind, in principle, IPV6 could have each "device" us its own IP, kind of 
like routing to you via MAC address. But.. In a practical sense, its 
still the same DNS system being used for it.

-- 
void main () {
   If Schrödingers_cat is alive or version > 98 {
     if version = "Vista" {
       call slow_by_half();
       call DRM_everything();
     }
     call functional_code();
   }
   else
     call crash_windows();
}

<A HREF='http://www.daz3d.com/index.php?refid=16130551'>Get 3D Models, 
3D Content, and 3D Software at DAZ3D!</A>

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Le 14/05/2010 18:37, Darren New nous fit lire :
> 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?

I'm feeling fear... I know them all...
SDH should be cited with SONET if you go that way!


IP is not designed for large networks of today.
It has been designed for hierarchy of networks.
Getting ride of classes was just one way to avoid doomsday for a time.
Address allocation was always done by delegation along the hierarchical
path...
Then came NAT... but it won't stand long either.

>> 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.
> 
Rejoice, the end of IPv4 addresses is coming... less than 1 year of
available blocs for some continents... 2 years for the lucky ones!

Get your visa & mastercard ready to pay for a routable ipv4 if ipv6 does
not happens transparently for joe-user and you want a public server!

>> 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.
> 

What is worst with IP: every interface of a system need one, not the
system itself, but every interface! You do not try to reach a system,
but a door to that system... and the same door number can be reused by
others... lame!

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On Fri, 14 May 2010 13:53:14 -0700, Patrick Elliott wrote:

> On 5/14/2010 1:12 AM, Invisible wrote:
>>> Yes. Who served the IP address to your machine? Time Warner San Diego?
>>> I doubt it.
>>
>> AFAIK, IP addresses are assigned by a central allocation agency.
>>
>> Sure, you don't usually talk to them directly; usually you use one of
>> the IP addresses from the block assigned to your ISP. 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.
> Mind, in principle, IPV6 could have each "device" us its own IP, kind of
> like routing to you via MAC address. But.. In a practical sense, its
> still the same DNS system being used for it.

That's one of the nice features of IPv6 (taken from IPX, actually, from 
what I've read, that essentially did the same thing).

Jim

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