Subject: RE: IP network address assignments/allocations information?

From: "Polinsky, Steven" <[email-masked]>
Date: Mon, 6 Dec 1999 18:20:15 -0500

I'm not advocating one technology over another. I am claiming that in the
IPV4/Private/Public/NAT world, a bigger pool of Private space would be a big
help to many organizations.

Steven

Steven M. Polinsky
Vice President, Information Technology
Goldman, Sachs & Co.
180 Maiden Lane
New York, NY 10038
212-902-3669

-----Original Message-----
From: Jeffrey Altman [mailto:[email-masked]]
Sent: Monday, December 06, 1999 6:08 PM
To: Polinsky, Steven
Cc: 'Perry E. Metzger'; J. Noel Chiappa; [email-masked]
Subject: RE: IP network address assignments/allocations information?

> To me the biggest problem here, is the common situation such that
companies
> have separate (and necessary) Internet and Remote Access firewalls. RA
> firewalls exist in multiple global locations within an enterprise.
> 
> Multiple instances of the same Private addresses would enter (or exit) the
> enterprise network via Private lines from different companies if not for
> careful configuration management across and negotiation between "NAT
> Administrators", within the enterprise, and between enterprises. The most
> difficult part is the negotiation with client/vendor site NAT Admins as to
> who should NAT which addresses into which addresses. We often need to
> negotiate between 3 RA connected companies. Not only is this painful, but
> one can never sleep comfortably, knowing that a NAT Admin at a 3rd company
> will not make a mistake and connect someone new at our NATed address. 
> 
> There are not enough Private Addresses to go around.

This sounds to me like more of an argument why private addresses
should be used on networks connected to public networks.  It is not
an argument for more private networks but for the move to IPv6 and
the banning of NATs.

    Jeffrey Altman * Sr.Software Designer * Kermit-95 for Win32 and OS/2
                 The Kermit Project * Columbia University
              612 West 115th St #716 * New York, NY * 10025
  http://www.kermit-project.org/k95.html * [email-masked]

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From: "Josh Duffek" <[email-masked]>
Date: Mon, 6 Dec 1999 17:44:20 -0600

In a perfect world with proper network design I would have to disagree with
you.  I believe that properly subnetted the private address space allocated
would be enough.  Classful routing and VLSM should take care of this
problem.

But in the real world, with not so great network design I have seen many
cases where more space is needed.

Josh
[email-masked]

> From: Polinsky, Steven [mailto:[email-masked]]
> Sent: Monday, December 06, 1999 5:20 PM
> To: [email-masked]'

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From: "Josh Duffek" <[email-masked]>
Date: Mon, 6 Dec 1999 17:44:20 -0600

Josh
[email-masked]

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From: "Josh Duffek" <[email-masked]>
Date: Mon, 6 Dec 1999 18:05:20 -0600

Classles routing rather :)

Josh

> From: Josh Duffek [mailto:[email-masked]]
> Sent: Monday, December 06, 1999 5:44 PM
> To: Polinsky, Steven; [email-masked]

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From: "Josh Duffek" <[email-masked]>
Date: Mon, 6 Dec 1999 18:05:20 -0600

Josh

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From: Keith Moore <[email-masked]>
Date: Mon, 06 Dec 1999 23:40:10 -0500

> help to many organizations.

I think this is a fine idea.  What we need is to reserve enough private
address space so that each organization can have its own chunk of private 
address space.  That way, organizations won't have to fiddle with
their mapping tables to avoid conflicts!   In fact, I think we should
reserve the entire remainder of IPv4 address space, and most of IPv6
address space, for use as private address space.  Of course, for the sake
of routing scalability it will be necessary to assign most of this private 
address space out of larger chunks that are assigned to ISPs, but except
for that little detail, it sounds like a wonderful idea!

(end sarcasm)

seriously, the only way you can have private address space large enough
to map all of the other private address spaces (that you wish to talk
to) into your private address space, is to reserve a portion of
your own private address space that is large enough for all of the 
other private address spaces (that you wish to talk to) combined.   
problem is, everyone else's private address space is potentially
as large as your own.  making the private address space larger won't
solve that problem.  it might give you a few months' breathing
room, but eventually you end up having to limit the amount of 
address space that any organization can use, so that there's room to 
map it into everyone else's address space. once you do that
you might as well just assign a chunk of address space to each
organization.  and for that we need IPv6.  

Keith

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From: Keith Moore <[email-masked]>
Date: Mon, 06 Dec 1999 23:40:10 -0500

(end sarcasm)

Keith

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From: Harald Tveit Alvestrand <[email-masked]>
Date: Tue, 07 Dec 1999 08:58:40 +0100

>cases where more space is needed.

You've got 3 blocks already.
 From RFC 1918:

3. Private Address Space

    The Internet Assigned Numbers Authority (IANA) has reserved the
    following three blocks of the IP address space for private internets:

      10.0.0.0        -   10.255.255.255  (10/8 prefix)
      172.16.0.0      -   172.31.255.255  (172.16/12 prefix)
      192.168.0.0     -   192.168.255.255 (192.168/16 prefix)

Are your customers using *all* those blocks?

                   Harald

--
Harald Tveit Alvestrand, EDB Maxware, Norway
[email-masked]

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From: Harald Tveit Alvestrand <[email-masked]>
Date: Tue, 07 Dec 1999 08:58:40 +0100

3. Private Address Space

                   Harald