Private Address Question
Dave
I have the following question:
Can any IP address range be configured as a private address space?
I know that there are reserved non routable IP addresses such as 10.x.x.x
or 192.168.x.x. But is there a means or technique that I could use any IP
range I wanted as a private address space.
Thanks in advance for your help.
Dave
Dave
je@n
"Dave" <dave...@att.net> wrote in message
news:Iv5x8.45648$QC1.3...@bgtnsc04-news.ops.worldnet.att.net...
I don't understand. For every class there are private ranges, so for every
specific situation you can take the range that fits best (large number of
clients, large number of subnetworks and so on..)
What's the reason?
Je@n
Dave
"je@n" <horzj...@hotmail.com> wrote in message
news:aa30m3$1liu$1...@scavenger.euro.net...
Keith W. McCammon
>
> I know that there are reserved non routable IP addresses such as
10.x.x.x
> or 192.168.x.x. But is there a means or technique that I could use any IP
> range I wanted as a private address space.
In theory, yes. You can use whatever you want. Just don't expect things to
work correctly if you connect to an external network.
Barry Margolin
Dave <dave...@att.net> wrote:
> Can any IP address range be configured as a private address space?
>
> I know that there are reserved non routable IP addresses such as 10.x.x.x
>or 192.168.x.x. But is there a means or technique that I could use any IP
>range I wanted as a private address space.
If you use the same address range on your LAN as the public addresses of
some other organization, you won't be able to communicate with that
organization. All the machines on your LAN will think that addresses in
that range are local, so they won't send the traffic out to the Internet.
The thing that makes the "official" private address ranges special is that
no one should try to use them as their public addresses. So the fact that
lots of different organizations are using them shouldn't cause problems
(although it occasionally does -- when two such organizations merge, and
try to connect their LANs together).
--
Barry Margolin, bar...@genuity.net
Genuity, Woburn, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.
Donald McLachlan
I'm not exactly sure what you want to accomplish, and I'd not recommend it unless you
think very carefully about what you are doing, but I can think of a couple of ways.
1 - you could NAT any address space you want into your official address space.
2 - to join 2 separate sites which have separate routable address spaces, you could
run a (IPSec or IP-in-IP) tunnel between the 2 sites routers (end point being
official addresses) and subnet any address space you want behind the two routers
to make it look like one contiguous "private" address space. Because the
"tunneled" address space is hidden from intermediate routers, they are effective
"private".
--
Donald McLachlan E-mail Donald.M...@crc.ca
Communications Research Centre / RNS Tel (613) 998-2845
3701 Carling Ave., Fax (613) 998-9648
Ottawa, Ontario
K2H 8S2
Canada
Kristian Rask
You can just do it.
However...
- try using Microsofts address range.
- then try going www.microsoft.com.
there is only two imediate drawbacks
You cant ever visit the servers that really has these IP's
You cant expect that anyone else will route data to or from you, as
they will end in the same situation if they do.
Your ISP connection will be trough an IP the ISP assigns, and you will
have to use NAT.
If your ISP's equipment behave badly cause of your router, your ISP
will get pissed... however.. if your 200$ NAT router can piss of the
ISP's equipment, you might want to change ISP. IF they REALLY listen
and react to rip and stuff from their clients, then run away
screaming.
regards
Kristian
regards
Kristian
---------------------------------------------
In order to send email you must edit my mail address
Barry Margolin
Kristian Rask <nospam...@mediac.dk.> wrote:
>You cant expect that anyone else will route data to or from you, as
>they will end in the same situation if they do.
The latter is true for RFC 1918 addresses. That's what makes them
"private".
>Your ISP connection will be trough an IP the ISP assigns, and you will
>have to use NAT.
That's also true of RFC 1918 addresses.
The only difference between using RFC 1918 addresses and using some other
addresses privately is the inability to reach the *real* user of the other
addresses.
Kristian Rask
English is not my first language, so..
On Tue, 23 Apr 2002 21:16:19 GMT, Barry Margolin <bar...@genuity.net>
wrote:
i unfortunately have a real problem seing in what way the above
comments are contradicting (or the otherway arround, more to the
point, more precise) than what i wrote. ?????
What am i missing ?
regards
Kristian aka The eternal newbie
Barry Margolin
Kristian Rask <nospam...@mediac.dk.> wrote:
>On Tue, 23 Apr 2002 21:16:19 GMT, Barry Margolin <bar...@genuity.net>
>wrote:
>>addresses privately is the inability to reach the *real* user of the other
>>addresses.
>
>comments are contradicting (or the otherway arround, more to the
>point, more precise) than what i wrote. ?????
>
>What am i missing ?
The OP asked a question specifically about using non-standard private
addresses. Your answer mostly described some issues with using private
addresses in general, whether or not they're the standard ones (RFC 1918)
or non-standard ones. They're not usually considered "problems", since
they're usually the reason you choose to use private addresses rather than
routable addresses.
Kristian Rask
On Wed, 24 Apr 2002 14:23:59 GMT, Barry Margolin <bar...@genuity.net>
wrote:
>The OP asked a question specifically about using non-standard private
>addresses. Your answer mostly described some issues with using private
>addresses in general, whether or not they're the standard ones (RFC 1918)
>or non-standard ones. They're not usually considered "problems", since
>they're usually the reason you choose to use private addresses rather than
>routable addresses.
I see 4 possibilities here.
- I dont understand the original question.
- I really have no clue about IP
- You have a understanding so deep that your answers are completely
beyond what my brain can comprehend
- We are not talking about the same OP
I have answered a question about what happens if you chose to use
someones real ip addresses for your private lan (in a way that works
and doesnt harm other than your self)
regards
Kristian
Martin Djernaes
Kristian Rask wrote:
> >The OP asked a question specifically about using non-standard private
> >addresses. Your answer mostly described some issues with using private
> >addresses in general, whether or not they're the standard ones (RFC 1918)
> >or non-standard ones. They're not usually considered "problems", since
> >they're usually the reason you choose to use private addresses rather than
> >routable addresses.
>
> I see 4 possibilities here.
What Barry is answering is that it depends on what you are talking
about. The OP (Dave) was asking, pure academicly, if another range of IP
adresses could be made private. See, where the Internet define via RFC
1918 that some ranges are private, there is no such restrictions if you
talk about IP (outside the Internet). So one is the usage (we have
agreed upon these ranges being private) and the other is technically
(there is no such thing as private addresses).
So when you say that "it won't work", you are right ... on the Internet,
but if we would like oto, we could take any unused IP address space and
call it "private" - and that would work.
Martin
Dave
Dave
"Martin Djernaes" <mar...@djernaes.dk> wrote in message
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