Re: v6 support (was Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...)))

2003-04-03 Thread Eric Rosen

Steve> I  can't get upset  about Microsoft  declining to  ship poorly-tested
Steve> code.  Given how many security  holes are due to buggy, poorly-tested
Steve> programs, I applaud anyone who takes that seriously. 

Well, suppose they were to ship IPv6 without IPsec, on the grounds that they
didn't have the testing resources  for IPsec.  Would you still be applauding
them?  Or would you be questioning whether they have their priorities right? 

Features always fall off due to the inability to allocate sufficient testing
resources,  but a vendor  does have  some choice  over which  features those
are. 







Re: v6 support (was Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...)))

2003-04-03 Thread Steven M. Bellovin
In message <[EMAIL PROTECTED]>, Keith Moore writes:
>> >Then there's the problem that when a 800-pound gorilla ships code,
>> >that code largely defines expectations for what will and will not
>> >work in practice- often moreso than the standards themselves.
>> >  
>> >
>> Strange as I feel defending Microsoft, I actually think it's
>> commendable that they implemented IPv6 at all; it's not as if there's
>> a lot of market demand for it yet. 
>
>I'm certainly glad that they've done so; however most of their
>competitors are shipping v6 also, and some have been doing so for
>considerably longer than MS.  About the only major vendor that isn't
>shipping v6 seems to be Palm (shame on them!). 
>
Keith, I can't get upset about Microsoft declining to ship 
poorly-tested code.  Given how many security holes are due to buggy, 
poorly-tested programs, I applaud anyone who takes that seriously.


--Steve Bellovin, http://www.research.att.com/~smb (me)
http://www.wilyhacker.com (2nd edition of "Firewalls" book)





RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-03 Thread Jeroen Massar
Margaret Wasserman [mailto:[EMAIL PROTECTED] wrote:

> Hi Jeroen,
> 
> > > >Most OS's require a (unique) hostname to be entered/automatically
> > > >generated on install
> > > >
> > > False.
> >
> >And is there any reasoned argument instead of the simple 'false'?
> 
> Some examples certainly would have been helpful...
> 
> I can give one common example.  Special-purpose client systems
> (consumer devices, car infotainment systems, etc.) seldom require
> or configure a DNS name.
> 
> In most IPv4 situations, though, these types of systems would
> receive their addresses through DHCP, usually through an ISPs
> DHCP server.  In many cases, ISPs provide generic (e.g.
> hostNNN.isp.com) host names for all of the addresses in their
> DHCP pool, so that reverse lookups will work, etc.
> 
> But the operating system and TCP/IP stack on the device do
> not actually require that a hostname be configured.

My thought went out from both the manual page of a typical Unix box:
8<---
 Hostname is used to either set or display the current
 host or domain name of the system. This name is used
 by many of the networking programs to identify the
 machine. The domain name is also used by NIS/YP.
--->8

And the fact that windows boxes nowadays also
autogenerate a hostname based on some of the
properties of the machine to overcome clashes
in the SMB/CIFS namespace. Note that this still
has nothing to with IP.

Phones and other devices that could be used
for transfering files usually autogenerate a
hostname based on their cellphonenumber.

But indeed there are bound to be apparatus which 
don't have such a feature, thus one will have to
type the full IP then if you want to do something.
Fortunatly finding out all the hosts on a subnet
isn't that trivial anymore ff02::1 ;)
But I wonder how consumer friendly that is...

Greets,
 Jeroen





RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-03 Thread Margaret Wasserman
Hi Jeroen,

> >Most OS's require a (unique) hostname to be entered/automatically
> >generated on install
> >
> False.
And is there any reasoned argument instead of the simple 'false'?
Some examples certainly would have been helpful...

I can give one common example.  Special-purpose client systems
(consumer devices, car infotainment systems, etc.) seldom require
or configure a DNS name.
In most IPv4 situations, though, these types of systems would
receive their addresses through DHCP, usually through an ISPs
DHCP server.  In many cases, ISPs provide generic (e.g.
hostNNN.isp.com) host names for all of the addresses in their
DHCP pool, so that reverse lookups will work, etc.
But the operating system and TCP/IP stack on the device do
not actually require that a hostname be configured.
Margaret






RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-03 Thread Jeroen Massar
John Stracke wrote:
> Jeroen Massar wrote:
> 
> >>Ad-hoc networks are another similar case, where two machines 
> >>are connected via ad-hoc wireless, bluetooth, firewire,
> >>or similar.
> >>
> >>
> >In any other way do you like remembering and typing over 128bit
> >addresses?? :)
> >
> :: is your friend.  If you're building an ad hoc, point-to-point 
> network, you can pick convenient addresses.

:: as in all 0's which corresponds to 'not bound'?
I don't see how you are going to communicate between
two hosts with a unbound IP. Especially in a ad-hoc
network where everything should be configured automatically.

> >Most OS's require a (unique) hostname to be entered/automatically
> >generated on install
> >
> False.

And is there any reasoned argument instead of the simple 'false'?

Greets,
 Jeroen





Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-03 Thread Fredrik Nyman
On 2 Apr 2003 at 18:10, Keith Moore wrote:

> > The lack of IPv6 literal address support in the version of wininet.dll
> > that shipped with Windows XP was for reasons of engineering
> > expediency, 
> 
> in other words, MS deliberately shipped a broken product.

Oh, look, release notes, known issue statements, bugtracker entries...

Seems like everybody is deliberately shipping broken products...

-- 
Fredrik Nyman
PacketFront Sweden AB
http://www.packetfront.com/




RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Brian Zill
Hi Jeroen,

The lack of IPv6 literal address support in the version of wininet.dll
that shipped with Windows XP was for reasons of engineering expediency,
and not any political policy decision.  To the best of my knowledge,
Microsoft hasn't said one way or another as to whether or not we plan to
support IPv6 literal addresses in URLs in future releases.

I do, however, also remember a discussion on one of the IPv6 mailing
lists about this, and it seemed that there were several members of the
IPv6 community at large who thought it was great that we weren't
currently supporting them.  Apparently there are those who think
hard-coding IP addresses (of any version) in URLs is a bad idea.
Perhaps this is the discussion you are remembering.

--Brian

> -Original Message-
> From: Jeroen Massar [mailto:[EMAIL PROTECTED] 
> Sent: Wednesday, 02 April, 2003 07:19
> To: 'Spencer Dawkins'; [EMAIL PROTECTED]
> Cc: IPv6 Feedback Alias
> Subject: RE: Thinking differently about the site local 
> problem (was: RE: site local addresses (was Re: Fw: Welcome 
> to the InterNAT...)) 
> 
> 
> Spencer Dawkins wrote:
> 
> > Hi, Jeroen,
> > 
> > Are you talking about ftp://ftp.rfc-editor.org/in-notes/rfc2732.txt 
> > (PS)?
> > 
> > My quick read of this RFC is that it says "don't use IPv6 literals 
> > without enclosing them in brackets", as in
> > 
> >   host  = hostname | IPv4address | IPv6reference
> >   ipv6reference = "[" IPv6address "]"
> > 
> > But that's not quite the same thing you said: "never use 
> IPv6 IP's in 
> > URL's".
> > 
> > If you're talking about another reference, could you provide it? A 
> > quick RFC search for "IPv6 URL" turned up only this RFC...
> 
> Yes, though I can't seem to google up any references. Except 
> for: 
> http://www.microsoft.com/windowsxp/pro/techinfo/administration
/ipv6/defa
ult.asp

"Q: How can I force IPv6 connections using my Web browser?"  "For
applications other than Internet Explorer: Connect using a literal IPv6
address. URLs that use the format for literal IPv6 addresses described
in RFC 2732, "Format for Literal IPv6 Addresses in URLs," are not
supported by the version of Internet Explorer provided with Windows XP."

There was some discussion about this deprecation as the Techpreviews
(Win2k/NT4) did support literal url's. The XP version and up though
won't support it to overcome one major 'problem': website 'designers'
embedding IP's inside websites to 'speed things up' (go figure). And
there where a number of other reasons for deciding so. Unfortunatly I
can't find the messages which where sent to a mailinglist about this
discussion which also contained why they decided this. Note that
wininet.dll doesn't support it that's why IE doesn't either...

MS CC'd, they can best explain the rationale behind it.

Greets,
 Jeroen

PS: Is 'google' already an official english verb? :)






RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Tony Hain
Jeroen Massar wrote:
> Tony Hain [mailto:[EMAIL PROTECTED] wrote:
> 
> > Jeroen Massar wrote:
> > > ... That's also why IE in XP doesn't support it.
> > 
> > Making claims that you know nothing about, only exposes 
> your lack of 
> > clue.
> 
> Fortunatly I don't have to resolve to personal accusations
> to get my point across. I cc:'d the people who really
> know how the stuff works so they could comment on these statements. :)

I was the IPv6 program manager for what ended up shipping in XP, and
literals in wininet didn't make it for lack of testing resources. 

Tony






RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Jeroen Massar
Tony Hain [mailto:[EMAIL PROTECTED] wrote:

> Jeroen Massar wrote:
> > ... That's also why IE in XP doesn't support it. 
> 
> Making claims that you know nothing about, only exposes your lack of
> clue.

Fortunatly I don't have to resolve to personal accusations
to get my point across. I cc:'d the people who really
know how the stuff works so they could comment on these statements. :)

Greets,
 Jeroen




RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Jeroen Massar
Daniel Senie wrote:



> Ad-hoc networks are another similar case, where two machines 
> are connected via ad-hoc wireless, bluetooth, firewire,
> or similar. I'd think it might be useful to be able to
> serve web pages between two laptops on a train without 
> requiring a naming service to be present. Perhaps that won't 
> be an issue in the brave new world.

Your naming service will probably be of the broadcast kind
In any other way do you like remembering and typing over 128bit
addresses?? :)
Most OS's require a (unique) hostname to be entered/automatically
generated on install to identify the host to the rest of the
system/network/users. This note can also be used to identify
it over your file sharing protocol. SMB/CIFS comes with it's
own version for example. Most Gnutella/* I don't know what
filesharing protocols also have a naming system based on
the users login name etc. Heck even your bluetooth cellphone
nicely announces it's name + address around the room when
you accidentally forget to turn it off. Last weekend some
unnamed person was even spamming all the people at the
national ISP Karting competition over bluetooth. Good guess
to try and spam there as most ISP people are fond of geek
tools but also forget to turn their toys off/protect them :)

> It just seems to me there is some utility in having this 
> capability (and  others must have thought so since we have
> an RFC describing the formatting). Let's think hard before
> deciding we are sure there are no useful cases left.

Ofcourse there is a need for this, but like SL there are some
ways of solving the current ways of doing it. Better clean
up now than be sorry in the end. Eg alcatel adsl modems have a
web&telnet-interface for configuring them, then again being
a SOHO product it should be capable of autoconfiguration.
One thing that's for sure is that you can't use two of those
devices in the same network as the IP's will always be 10.0.0.138
with no other way to change it than by serial or the network.
As we did invent DAD there is no such 'defacto' IP for those
boxes to configure themselves with any more... 
We could use ping6 ff02::1%eth0, but tell that to a homeuser...

Greets,
 Jeroen




RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Jeroen Massar
Keith Moore wrote:



> I could certainly make a case for some apps to have their own naming
> systems and their own name-to-address lookup mechanisms independent of
> DNS, or more generally, for alternate means of mapping resource names
> (say URNs) to IP addresses that did not involve DNS names or DNS
> queries.  But it's difficult to believe that such apps would 
> not employ
> DNS names at all - if nothing else, for initial configuration.

You might almost forget about SMB/CIFS :)
No DNS in there and most people use it daily without even realising it.

Greets,
 Jeroen




RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Daniel Senie
At 10:18 AM 4/2/2003, Jeroen Massar wrote:
Spencer Dawkins wrote:

> Hi, Jeroen,
>
> Are you talking about
> ftp://ftp.rfc-editor.org/in-notes/rfc2732.txt (PS)?
>
> My quick read of this RFC is that it says "don't use IPv6
> literals without enclosing them in brackets", as in
>
>   host  = hostname | IPv4address | IPv6reference
>   ipv6reference = "[" IPv6address "]"
>
> But that's not quite the same thing you said: "never use IPv6
> IP's in URL's".
>
> If you're talking about another reference, could you provide it?
> A quick RFC search for "IPv6 URL" turned up only this RFC...
Yes, though I can't seem to google up any references. Except for:
http://www.microsoft.com/windowsxp/pro/techinfo/administration/ipv6/defa
ult.asp
"Q: How can I force IPv6 connections using my Web browser?"

"For applications other than Internet Explorer: Connect using a literal
IPv6 address. URLs that use the format for literal IPv6 addresses
described in RFC 2732, "Format for Literal IPv6 Addresses in URLs," are
not supported by the version of Internet Explorer provided with Windows
XP."
There was some discussion about this deprecation as the
Techpreviews (Win2k/NT4) did support literal url's.
The XP version and up though won't support it to overcome
one major 'problem': website 'designers' embedding IP's
inside websites to 'speed things up' (go figure).
And there where a number of other reasons for deciding so.
Unfortunatly I can't find the messages which where sent
to a mailinglist about this discussion which also contained
why they decided this. Note that wininet.dll doesn't support
it that's why IE doesn't either...
MS CC'd, they can best explain the rationale behind it.
This line of reasoning troubles me. One of the ways in which numeric IP 
addresses are useful in URLs is for talking to systems which are not yet 
fully configured (e.g. configuring routers and such). I'm sure Microsoft's 
answer to this is "Use UPNP" but that may not be a universally sufficient 
answer. Others will say "Use Zeroconf" which may also not be sufficient. I 
guess I'm just really uncomfortable requiring name spaces in temporary and 
disconnected networks as an absolute requirement.

Ad-hoc networks are another similar case, where two machines are connected 
via ad-hoc wireless, bluetooth, firewire, or similar. I'd think it might be 
useful to be able to serve web pages between two laptops on a train without 
requiring a naming service to be present. Perhaps that won't be an issue in 
the brave new world.

It just seems to me there is some utility in having this capability (and 
others must have thought so since we have an RFC describing the 
formatting). Let's think hard before deciding we are sure there are no 
useful cases left.





RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Tony Hain
Jeroen Massar wrote:
> ... That's also why IE in XP doesn't support it. 

Making claims that you know nothing about, only exposes your lack of
clue.

Tony





RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Jeroen Massar
Keith Moore wrote:

> > Sounds like you both are arguing that the DNS has become
> > "embedded" and the applications that use IP are unusable 
> > without a working DNS.  
> 
> as a practical matter, this was true even in IPv4.  yes, you can
> often use address literals in either v4 or v6 apps, but this isn't
> practical for ordinary users on an ordinary basis.  and in both v4 and
> v6, several essential apps (e.g. email, the web) have explicit
> dependencies on DNS.  yes you can use address literals in email
> addresses and URLs but there is no assurance that an email address or
> URL with an address literal is equivalent to the same address or URL
> with a domain instead of the address. Both email and the web define
> their resources in relation to a DNS name, not relative to a host or
> address.
> 
> of course it is possible to write apps that do not use DNS, 
> but this is rarely done.

Fortunatly we still all are humans and like names, not numbers :)
We'll let the numbers to computers (big fast math machines)
Our brains are more advanced and just can't cope with numbers any more
;)

Greets,
 Jeroen




RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Jeroen Massar
Keith Moore [mailto:[EMAIL PROTECTED] wrote:

> > There was some discussion about this deprecation as the
> > Techpreviews (Win2k/NT4) did support literal url's.
> > The XP version and up though won't support it to overcome
> > one major 'problem': website 'designers' embedding IP's
> > inside websites to 'speed things up' (go figure).
> 
> perfectly reasonable thing to do.  browsers that don't support it are
> broken.

It's perfectly reasonable to not support RFC2732? or?

Greets,
 Jeroen




Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Bill Manning
% > >   Are the apps for which IPv6 is enabled that -can not-
% > >   use address literals?  If so, then Steve is wrong and
% > >   the DNS has become critical infrastructure to the working
% > >   of the Internet.
% > 
% > anyone who believes that the DNS is not critical infrastructure for just 
% > about every single purpose the Internet is used for is either living in a 
% > fantasy world or has redefined the "Internet" to be something that's 
% > strictly at layer 3 and below.
% 
% agreed.  but there's a difference between saying that DNS is critical
% infrastructure and that it's appropriate to use DNS every time an address is
% needed.  DNS is necessary, not sufficient.
% 
% Keith

to pass bits, in the IPv4 world, DNS is -NOT- critical.
no application forbids address literals and every app
will allow address literals to be used.  Couple this with
the fact that IPv4 addresses are within the scope of human
comprehension, i.e. I can remember 128.9.160.160

with IPv6, the addresses are long enough to not be human
friendly, e.g.  2001:0478:6: is about as much as I remember
on my own...  I must use the DNS or my little yellow sticky note
to complete the address.  And there are intimations that some
applications now forbid the use of address literals, even
if bracketed.  

Sounds like you both are arguing that the DNS has become
"embedded" and the applications that use IP are unusable 
without a working DNS.  This assertion, if true, has ramifcations
beyond a simple requirement to have the latency of an extra
lookup against a third party.  (Can you say "Death to e2e!...
sure you can :)


--bill
Opinions expressed may not even be mine by the time you read them, and
certainly don't reflect those of any other entity (legal or otherwise).



RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Jeroen Massar
Spencer Dawkins wrote:

> Hi, Jeroen,
> 
> Are you talking about
> ftp://ftp.rfc-editor.org/in-notes/rfc2732.txt (PS)? 
> 
> My quick read of this RFC is that it says "don't use IPv6
> literals without enclosing them in brackets", as in
> 
>   host  = hostname | IPv4address | IPv6reference
>   ipv6reference = "[" IPv6address "]"
> 
> But that's not quite the same thing you said: "never use IPv6
> IP's in URL's".
> 
> If you're talking about another reference, could you provide it?
> A quick RFC search for "IPv6 URL" turned up only this RFC...

Yes, though I can't seem to google up any references. Except for:
http://www.microsoft.com/windowsxp/pro/techinfo/administration/ipv6/defa
ult.asp

"Q: How can I force IPv6 connections using my Web browser?"

"For applications other than Internet Explorer: Connect using a literal
IPv6 address. URLs that use the format for literal IPv6 addresses
described in RFC 2732, "Format for Literal IPv6 Addresses in URLs," are
not supported by the version of Internet Explorer provided with Windows
XP."

There was some discussion about this deprecation as the
Techpreviews (Win2k/NT4) did support literal url's.
The XP version and up though won't support it to overcome
one major 'problem': website 'designers' embedding IP's
inside websites to 'speed things up' (go figure).
And there where a number of other reasons for deciding so.
Unfortunatly I can't find the messages which where sent
to a mailinglist about this discussion which also contained
why they decided this. Note that wininet.dll doesn't support
it that's why IE doesn't either...

MS CC'd, they can best explain the rationale behind it.

Greets,
 Jeroen

PS: Is 'google' already an official english verb? :)




RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Spencer Dawkins
Hi, Jeroen,

Are you talking about
ftp://ftp.rfc-editor.org/in-notes/rfc2732.txt (PS)? 

My quick read of this RFC is that it says "don't use IPv6
literals without enclosing them in brackets", as in

  host  = hostname | IPv4address | IPv6reference
  ipv6reference = "[" IPv6address "]"

But that's not quite the same thing you said: "never use IPv6
IP's in URL's".

If you're talking about another reference, could you provide it?
A quick RFC search for "IPv6 URL" turned up only this RFC...

Thanks,

Spencer

--- Jeroen Massar <[EMAIL PROTECTED]> wrote:
> Also there is a RFC which
> says to never use IPv6 IP's in URL's... That's also why
> IE in XP doesn't support it. "Host" is now an integral
> part of HTTP/1.1 and one can't even do without it anymore.



RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-02 Thread Jeroen Massar
Michael Richardson wrote:

> -BEGIN PGP SIGNED MESSAGE-
> 
> 
> > "Bill" == Bill Manning <[EMAIL PROTECTED]> writes:
> Bill> Are the apps for which IPv6 is enabled that -can not-
> Bill> use address literals?  If so, then Steve is wrong and 
> 
>   yes.
>   Both IPv4 and IPv6 web browsers behave differently if you do,
> for instance:
> http://192.139.46.2/
> vs  http://www.sandelman.ca/
> 
>   A different Host: header is sent, and therefore one gets a 
> different 
> (virtual) web site.

Configure your server better than :) (eg use _default_ )
HTTP goes by name, not by IP. Also there is a RFC which
says to never use IPv6 IP's in URL's... That's also why
IE in XP doesn't support it. "Host" is now an integral
part of HTTP/1.1 and one can't even do without it anymore.

> Of course, we have no need of this in IPv6, since
> 2^64 web sites per LAN is plenty, but the protocol still 
> exists to do it.
>   Can we change this in IPv6? Maybe.

I don't think many hosters will like configuring 2^64 addresses
on their webservers, even though it is possible.

One neat thing about this is HTTPS though, as there are now enough
addresses for that. But fortunatly there are propositions for
enabling the "Host" header for different SSL sites even while
using the same IP (v4+v6 ofcourse).

Greets,
 Jeroen




Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-01 Thread Michael Richardson
-BEGIN PGP SIGNED MESSAGE-


> "Bill" == Bill Manning <[EMAIL PROTECTED]> writes:
Bill>   Are the apps for which IPv6 is enabled that -can not-
Bill>   use address literals?  If so, then Steve is wrong and 

  yes.
  Both IPv4 and IPv6 web browsers behave differently if you do,
for instance:
http://192.139.46.2/
vs  http://www.sandelman.ca/

  A different Host: header is sent, and therefore one gets a different 
(virtual) web site. Of course, we have no need of this in IPv6, since
2^64 web sites per LAN is plenty, but the protocol still exists to do it.
  Can we change this in IPv6? Maybe.

]   ON HUMILITY: to err is human. To moo, bovine.   |  firewalls  [
]   Michael Richardson, Sandelman Software Works, Ottawa, ON|net architect[
] [EMAIL PROTECTED] http://www.sandelman.ottawa.on.ca/ |device driver[
] panic("Just another Debian GNU/Linux using, kernel hacking, security guy"); [
-BEGIN PGP SIGNATURE-
Version: GnuPG v1.0.7 (GNU/Linux)
Comment: Finger me for keys

iQCVAwUBPopZtIqHRg3pndX9AQEc+wQA7lhFyoHXkIMopiYnh295B9R+8fpJxESt
dUGdIlbNUA6QwefQoHMkLo77teXn4cc2CxDI6RaE2t93FRxMOeJQUfgdT022UmQ/
co+cVhkyRXnweJb6DfwGfu3YHK/j+J7ScLw0TQ0FSAPFwGXHRbOmAppVD138hUJG
UXkPMLHDA/s=
=JyhG
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Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-01 Thread Bill Manning
% > > Let's assume that there is a FooBar server in SiteA.  If 
% > > another node in SiteA (NodeA) is communicating via a 
% > > multi-party application to a node in SiteB (NodeB), and wants 
% > > to refer NodeB to the FooBar server in SiteA, what does it do?
% > 
% > Send a name.
% 
% Not all addresses are published in DNS.
% DNS isn't a requirement for IP either.
% 
% Greets,
%  Jeroen

Quoth Steve... "There are no urgent DNS problems"

Are the apps for which IPv6 is enabled that -can not-
use address literals?  If so, then Steve is wrong and 
the DNS has become critical infrastructure to the working
of the Internet.  Otherwise, we should trapese down the
path of separation of topology locator from stack identifier.

and then revisit the DNS to see if its best used as a lookup
service between these two things... :)


--bill
Opinions expressed may not even be mine by the time you read them, and
certainly don't reflect those of any other entity (legal or otherwise).



Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-01 Thread J. Noel Chiappa
> From: [EMAIL PROTECTED]

>> Effectively this could be resolved by having one globally
>> unique identifier per node.

> Paging Noel Chiappa Paging Noel Chiappa ;)

Ah, one moment, if I may:

  "his books, he always said, contained the teachings of his master,
  Socrates; ... what [Plato] had to teach could only be learned as fire is
  kindled, by the touch of the flame itself."

- Mary Renault, 'Fire From Heaven'

The heart of all my knowledge on this matter I got from Jerry Saltzer, in
particular the paper that was reprinted as RFC-1498, "On the Naming and
Binding of Network Destinations". I have merely been repeating what seemed to
me a good idea.

Noel





Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-01 Thread J. Noel Chiappa
> From: Keith Moore <[EMAIL PROTECTED]>

> actually it's bad to force all apps to use DNS names - which are often
> less reliable, slower, less correct, and more ambiguous than IP
> addresses.

This is like saying it's bad to force people to use cars/busses/whatever
because they occasionally break, and everyone should walk everytime they need
to go anywhere, because that's more reliable. That works in an agrarian
society, but not an industrialized one.

We have multiple namespaces, each with different characteristics for the
names, for very good reasons. If we really need a name with characteristic A,
and we instead wind up using one with characteristic ~A "because it's more
reliable", then that's not good.

If we have a need for a name, and the optimal characteristics for that name
are those of an address (i.e. the topological location of an interface to the
network), then fine, use an address. If not, don't.

If the system for mapping from one namespace to another has problems, we
ought to fix it, not say "oh, we'll just stop using it".

Don't try and make everything into a nail because the hammer is the most
reliable tool you have.

Noel





Re: Thinking differently about the site local problem(was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-04-01 Thread John C Klensin


--On Monday, 31 March, 2003 09:01 -0800 Bill Manning 
<[EMAIL PROTECTED]> wrote:

Is may be worth noting that RIRs have -NEVER- made
presumptionson routability of the delegations they make.
I believe that, although I remember some arguments within ARIN 
back when I was on the AC about whether it was legitimate or 
rational to make allocations that were believed to be 
unroutable.   But I've gotten several private notes that lead me 
to believe that a lot of the community doesn't believe this or, 
more specifically, believes that everyone will fall into line 
and route any delegation that an RIR makes directly and, hence, 
that any RIR allocation will, de facto, become routable.

john









RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Michel Py
Margaret,

> Margaret Wasserman wrote:
> (2) Institutionalizing the need for split DNS. I understand
> that some network administrators choose to use split DNS
> today, but that doesn't meant that we want to build a
> requirement for split DNS it into the IPv6 architecture.

I don't think "Institutionalizing" is a good choice of words here. Split
DNS is not unique to site-local addresses, it's not even unique to
private addresses. I have seen several sites that have split DNS even
though they use public addresses only. Out of the 50 something distinct
sites that I administer, I think only one or two do not have split DNS.

> IMO, requiring the DNS infrastructure to be aware of and
> enforce topology boundaries is a poor architectural choice.

In theory, I agree but the fact of the matter is that it already is
aware of the topology and I don't see this changing any time soon. Don't
get me wrong: I do not like split DNS, but I have seen it on sites that
have a single public address per host. There also are multitudes of perl
scripts that parse custom zone files to make multiple different ones,
such as the very typical example below that will produce 2 set of zone
files:
(yes I know it does include NAT but keep in mind this is today's reality
too).

name inside_addr  outside_addr
www  192.168.1.2  209.233.126.65   # web server
ftp  192.168.1.3  209.233.126.65   # ftp server
sql  192.168.1.4  0.0.0.0
pop3 0.0.0.0  209.233.126.65

[parse with homebrew perl script]

zone file for inside DNS servers:
www  192.168.1.2  # web server
ftp  192.168.1.3  # ftp server
sql  192.168.1.4

zone file for outside DNS servers:
www  209.233.126.65   # web server
ftp  209.233.126.65   # ftp server
pop3 209.233.126.65

Again I'm not saying this is good but don't think it will be introduced
or institutionalized with site-local addresses; it's been around for a
long time.

Michel.




Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread S Woodside
On Monday, March 31, 2003, at 05:30  PM, Tony Hain wrote:

Let's assume that there is a FooBar server in SiteA.  If
another node in SiteA (NodeA) is communicating via a
multi-party application to a node in SiteB (NodeB), and wants
to refer NodeB to the FooBar server in SiteA, what does it do?
Send a name.
What if the address has no name? Suddenly running a DNS becomes a 
pre-requisite to running a network connected to the internet?

simon




RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Jeroen Massar
[EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] wrote:
> 
> On Tue, 01 Apr 2003 00:23:15 +0200, Jeroen Massar said:
> 
> > Effectively this could be resolved by having one globally
> > unique identifier per node. The underlying protocols should
> 
> Paging Noel Chiappa Paging Noel Chiappa ;)

Based on a quick Google I think I've just hit the flamepit...
Reading the, interresting on first sight, documents...

Greets,
 Jeroen




RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Jeroen Massar
Tony Hain wrote:

> Margaret Wasserman wrote:
> > I believe that you have misunderstood my point...  I'll try 
> > to explain further, although our friends in the applications 
> > area may be able to give better examples.
> > 
> > Let's assume that there is a FooBar server in SiteA.  If 
> > another node in SiteA (NodeA) is communicating via a 
> > multi-party application to a node in SiteB (NodeB), and wants 
> > to refer NodeB to the FooBar server in SiteA, what does it do?
> 
> Send a name.

Not all addresses are published in DNS.
DNS isn't a requirement for IP either.

> > If this is IPv6 with site-local addressing, NodeA may be 
> > speaking to the FooBar server using a site-local address.  
> > What happens if NodeA sends that site local address to NodeB?
> 
> Any app that sends topology locator information without understanding
> the topology is broken.



Thus RFC959 is broken? There goes my favourite transfer proto :)
And there are enough applications that are broken then.
Actually all the applications that need special processing
when traversing a NAT as those apps 
If those apps didn't pass an IP(/port) combo inside then
they wouldn't need special treatment by the NAT either.

We are actually getting to:
  Use a unique identifier that is topology independent.
Wasn't that where IP Addresses where meant for? A unique
address independent of topology...

Greets,
 Jeroen




Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Valdis . Kletnieks
On Tue, 01 Apr 2003 00:23:15 +0200, Jeroen Massar said:

> Effectively this could be resolved by having one globally
> unique identifier per node. The underlying protocols should

Paging Noel Chiappa Paging Noel Chiappa ;)




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RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Tony Hain
Margaret Wasserman wrote:
> I believe that you have misunderstood my point...  I'll try 
> to explain further, although our friends in the applications 
> area may be able to give better examples.
> 
> Let's assume that there is a FooBar server in SiteA.  If 
> another node in SiteA (NodeA) is communicating via a 
> multi-party application to a node in SiteB (NodeB), and wants 
> to refer NodeB to the FooBar server in SiteA, what does it do?

Send a name.

> 
> If this is IPv6 with site-local addressing, NodeA may be 
> speaking to the FooBar server using a site-local address.  
> What happens if NodeA sends that site local address to NodeB?

Any app that sends topology locator information without understanding
the topology is broken.

> 
> NodeB tries to reach the FooBar server at the SL address that 
> points to the FooBar server in SiteA.  But, within SiteB, 
> that same address may point to a non-existent subnet, to a 
> non-existent node or to an existing node in SiteB.  Scoped 
> routing doesn't stop NodeB from reaching the wrong node, it 
> guarantees that NodeB _will not_ reach the right node and 
> _may_ reach the wrong node.

In simple two party apps there will be no such confusion. If
applications insist on passing around information that they don't
understand, they will create the confusion you suggest.

> 
> The type of failure that NodeB will receive is different in 
> each case. If the address points to a non-existent subnet or 
> node, an ICMP error may or may not be generated and no 
> connection will be established (timeout), but if there is an 
> existing node in SiteB with the same address, NodeB will 
> receive some type error from that node (the node that NodeB 
> _thinks_ is the FooBar server), such as port not available, 
> connection reset, or an application-level error. Or, worse 
> yet, NodeB may not receive any error at all, and may never 
> know that it was speaking to the wrong node.

It is very likely that no error will be received, because most site
network managers block ICMP at the border anyway. 

> 
> Now, what if NodeA has a list of addresses for the FooBar 
> server (perhaps obtained through the use of split DNS) that 
> includes both site-local and global addresses?  Perhaps NodeA 
> will send the whole list of addresses to NodeB.  If NodeB 
> tries the site-local address first (as current IPv6 address 
> selection rules
> indicate) it will not reach the FooBar server.  However, it 
> could have reached the FooBar server using a global address.

If NodeB doesn't walk the list, it is broken. If the application on
NodeA passed topology locator information without understanding the
topology, it is broken.

> 
> Perhaps, you believe that NodeA should include intelligence 
> inside the application that knows NOT to send site-local 
> addresses to NodeB if NodeB is not in the same site?  If so, 
> how does NodeA find out that NodeB is not in the same site?

Since it didn't get a SL back for NodeB, there is no reason to provide
NodeB with a SL address. Those addresses are defined to be filtered, and
from the information that NodeA has, NodeB is on the outside of the
filter.

> 
> One proposal is that NodeA should only send addresses to 
> NodeB that are of the same or larger scope as the IP address 
> that NodeA is currently using to reach NodeB.  But, this has 
> problems, too:
> 
>  - It requires some fairly complicated changes to existing
>  applications to make them work properly on IPv6.

Changes that should be required anyway. Applications MUST NOT pass
around topology locator information without understanding what they are
doing.

>  - It requires applications to make address selection
>  choices based on the addresses in use at the
>  network layer.  Since there is an increasing desire
>  for applications to be unaware of the addresses used
>  at the network layer, and to survive changes in
>  those addresses (see SCTP, SIP, Mobile IP, 
> etc.), this
>  is not an architecturally sound mechanism.

If applications work from names, there is no need for a layer violation.
The stack is perfectly capable of figuring out the correct address to
use if it has a name to work from. Passing topology locator information
without a firm grasp of the topology is the architecturally unsound
issue here.

>  - It doesn't give a good answer for what the application
>  should do if it only has one address available
>  for the referral, and it is not of sufficient scope.

It absolutely does. When an app knows there is an insufficient scope, it
also knows that the connection is designed by the network manager to
fail. If the app developer can't figure out what to do when it is known
that a prospective member can't participate, it is not our job to spell
that out.

>  - It may not interact well with access control mec

RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Jeroen Massar
Keith Moore [mailto:[EMAIL PROTECTED] wrote:

> > > > Indeed, correctly coded applications will use a getaddrinfo()
> > > > and then a connect() in a loop until succesful. 
> > > 
> > > it's perfectly reasonable to connect to an address without first
> > > doing a DNS lookup.
> > 
> > I think nobody can't help you if you are using hardcoded IP's.
> > The only case you have an IP without DNS is when you get it
> > passed from another layer/entity (eg in a FTP from the server).
> 
> uh, no.   you can get IP addresses from any number of sources 
> other than DNS, including from other processes that exist on
> other nodes.  It's a perfectly reasonable thing to do.

Note the line about other layer/entity :)
Which is also one of the reasons why multi-faced dns isn't
the solution to this problem.

> > Can you identify those so that getaddrinfo() can be expanded
> > to fix these cases?
> 
> getaddrinfo() cannot be fixed.  it's major premise - that the host has
> the knowledge to make decisions about which of several 
> addresses is best to use - is fundamentally flawed, except in a
> few corner cases.

Effectively this could be resolved by having one globally
unique identifier per node. The underlying protocols should
then take care that messages are delivered to the host
described by the unique locator. The underlying protocols
could then, in case of your so called corner cases, or routing
troubles, based on all kinds of external information change
the underlying protocols so that the connection stays active
and messages can still be sent from A to B. Enter SCTP and
multihoming ? :)

This has nothing to do with sitelocal but more with the
fact that a host can have multiple paths from A to B: internet ;)

Greets,
 Jeroen




Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Matt Crawford
> > All right, how do you make internal site communications completely
> > oblivious to a change in your externally-visible routing prefix?
> 
> You declare that any app that keeps connections around for more than
> some time period T (say for 30 days) have a mechanism for
> detecting and recovering from prefix changes. That solves the
> problem for all apps, not just for local apps. 

Ah, well, if we're allowed to solve problems by fiat, let's just
declare that everyone "do the right thing" about site-local
addresses, automatically drop unauthorized packets, end hunger and
violence, and brush their teeth.



Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Valdis . Kletnieks
On Mon, 31 Mar 2003 15:49:03 CST, Matt Crawford <[EMAIL PROTECTED]>  said:
> > Let's assume that there is a FooBar server in SiteA.  If another
> > node in SiteA (NodeA) is communicating via a multi-party application
> > to a node in SiteB (NodeB), and wants to refer NodeB to the FooBar
> > server in SiteA, what does it do?
> 
> I thought we agreed, completely outside of IPv6 concerns, that
> shipping addresses in application data was bad. So NodeA refers
> NodeB to foobar-server.sitea.org. Q.E.F.

Yeah, we can agree all we want, but RFC959 still has a PORT command in it.

And until we've managed to move *all* the dain-bramaged applications to
Historical status, we're stuck with it.

And sometimes you have no *CHOICE* - if you're not shipping addresses around,
what *do* you put on a DNS A record?  This isn't facetiousness - it's a
real concern.  You can pass a hostname around instead of an address, and
when you look it up, you get back either a unique address (which you can
run with) or a site-local address (which you can't).  That's why RFC1918
has the prohibition against leaking private addresses into the DNS.

And let's face it guys - site-local is nothing but 1918 space on anabolic
steroids.  You thought it was hard to handle now, wait till it comes back
with a full blown case of "roid rage"



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RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Michel Py
> Eliot Lear wrote:
> Right up till the point where two companies start communicating
> with one another directly with site-locals.

No, no, no. That's exactly what we don't want site-locals to do.
Site-locals are not to communicate outside their own site, period.

Michel.




Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Matt Crawford
> Let's assume that there is a FooBar server in SiteA.  If another
> node in SiteA (NodeA) is communicating via a multi-party application
> to a node in SiteB (NodeB), and wants to refer NodeB to the FooBar
> server in SiteA, what does it do?

I thought we agreed, completely outside of IPv6 concerns, that
shipping addresses in application data was bad. So NodeA refers
NodeB to foobar-server.sitea.org. Q.E.F.



RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Jeroen Massar
Keith Moore wrote:

> > > Well, that is emphatically *NOT* what application developers 
> > > do. They do not just observe that it does not work, they try
> > > to work around, e.g. routing messages to a different address,
> > > at a different time, through a third party, or through a
> > > different protocol. 
> > 
> > Indeed, correctly coded applications will use a getaddrinfo()
> > and then a connect() in a loop until succesful. 
> 
> it's perfectly reasonable to connect to an address without first
> doing a DNS lookup.

I think nobody can't help you if you are using hardcoded IP's.
The only case you have an IP without DNS is when you get it
passed from another layer/entity (eg in a FTP from the server).
In any other way if you have multiple targets you can also
try all of those in a loop similar to getaddrinfo().

> even when you need to do a DNS lookup,
> getaddrinfo() doesn't always do what you need.

Can you identify those so that getaddrinfo() can be expanded
to fix these cases?

Greets,
 Jeroen




Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Matt Crawford
> All things SL is claimed to solve are solveable with unique
> addresses too, as long as you've got enough of them. The rest is
> just simple (perhaps tedious) work that every operations-aware
> person I know of would prefer to madness.

All right, how do you make internal site communications completely
oblivious to a change in your externally-visible routing prefix?

(Not everyone accepts that this is something necessary to achieve,
but some insist that it is.)



RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Margaret Wasserman
Hi Tony,

At 11:51 AM 3/31/2003 -0800, Tony Hain wrote:
Margaret Wasserman wrote:
> Of course, in the case of site-local addresses, you don't
> know for sure that you reached the _correct_ peer, unless you
> know for sure that the node you want to reach is in your
> site.
Since the address block is ambiguous, routing will assure that if you
reach a node it is the correct one. This FUD needs to stop!
I believe that you have misunderstood my point...  I'll try to explain
further, although our friends in the applications area may be able
to give better examples.
Let's assume that there is a FooBar server in SiteA.  If another
node in SiteA (NodeA) is communicating via a multi-party application
to a node in SiteB (NodeB), and wants to refer NodeB to the FooBar
server in SiteA, what does it do?
If this is IPv6 with site-local addressing, NodeA may be speaking
to the FooBar server using a site-local address.  What happens if
NodeA sends that site local address to NodeB?
NodeB tries to reach the FooBar server at the SL address that
points to the FooBar server in SiteA.  But, within SiteB, that
same address may point to a non-existent subnet, to a non-existent
node or to an existing node in SiteB.  Scoped routing doesn't stop
NodeB from reaching the wrong node, it guarantees that NodeB
_will not_ reach the right node and _may_ reach the wrong node.
The type of failure that NodeB will receive is different in each case.
If the address points to a non-existent subnet or node, an ICMP error
may or may not be generated and no connection will be established
(timeout), but if there is an existing node in SiteB with the same
address, NodeB will receive some type error from that node (the node
that NodeB _thinks_ is the FooBar server), such as port not
available, connection reset, or an application-level error. Or,
worse yet, NodeB may not receive any error at all, and may never
know that it was speaking to the wrong node.
Now, what if NodeA has a list of addresses for the FooBar server
(perhaps obtained through the use of split DNS) that includes
both site-local and global addresses?  Perhaps NodeA will send
the whole list of addresses to NodeB.  If NodeB tries the
site-local address first (as current IPv6 address selection rules
indicate) it will not reach the FooBar server.  However, it could
have reached the FooBar server using a global address.
Perhaps, you believe that NodeA should include intelligence inside
the application that knows NOT to send site-local addresses to NodeB
if NodeB is not in the same site?  If so, how does NodeA find out that
NodeB is not in the same site?
One proposal is that NodeA should only send addresses to NodeB that
are of the same or larger scope as the IP address that NodeA is currently
using to reach NodeB.  But, this has problems, too:
- It requires some fairly complicated changes to existing
applications to make them work properly on IPv6.
- It requires applications to make address selection
choices based on the addresses in use at the
network layer.  Since there is an increasing desire
for applications to be unaware of the addresses used
at the network layer, and to survive changes in
those addresses (see SCTP, SIP, Mobile IP, etc.), this
is not an architecturally sound mechanism.
- It doesn't give a good answer for what the application
should do if it only has one address available
for the referral, and it is not of sufficient scope.
- It may not interact well with access control mechanisms
that depend on using a site-local address to
reach services, as it errs on the side of not
sending site-local addresses, even when they
may be valid.
There are, IMO, three major problems (and several minor problems)
with the use of site-local addressing on globally connected networks:
(1) Routing protocol issues/complexity, such as the need to
handle ambiguous addresses in routing exchanges and
the need to maintain site "convexity".  These problems
can be avoided by avoiding site-border routers and
site-border nodes (as in the "moderate" proposal),
AND by placing site borders on OSPF/IS-IS area
boundaries or on AS boundaries.
(2) Institutionalizing the need for split DNS.  I understand
that some network administrators choose to use split
DNS today, but that doesn't meant that we want to build
a requirement for split DNS it into the IPv6 architecture.
IMO, requiring the DNS infrastructure to be aware of and
enforce topology boundaries is a poor architectural choice.
(3) The need for upper-layer protocols (transport, session and
application-layer prot

Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Stephen Sprunk
Thus spake "Eliot Lear" <[EMAIL PROTECTED]>
> Right up till the point where two companies start communicating with
> one another directly with site-locals.  Even if there is a router frob to
> keep the scopes scoped, you can bet it won't be used until someone
> realizes that the above problem occurred.

I've dealt with many companies interconnecting where both use RFC1918
space -- NAT is the first thing discussed.  You forget, these people are
connecting for a _business reason_ and there is real money to be lost if
they mess up.  It's a totally different engineering model than the public
Internet.

S

Stephen Sprunk "God does not play dice."  --Albert Einstein
CCIE #3723 "God is an inveterate gambler, and He throws the
K5SSSdice at every possible opportunity." --Stephen Hawking




Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Valdis . Kletnieks
On Mon, 31 Mar 2003 12:17:44 PST, Eliot Lear said:
> Right up till the point where two companies start communicating with one 
> another directly with site-locals.  Even if there is a router frob to 
> keep the scopes scoped, you can bet it won't be used until someone 
> realizes that the above problem occurred.

Well.. the same thing is true for 2 companies that get merged and both have
their 10/8 and 192.168/16 nets - then the router frobs get used.  I've heard
of one poor network engineer that had *5* 1:1 NATs separating one end of the
company from the other.

And of course, we all know that all RFC1918 users are conscientious about
filtering at their border routers.

"It's deja vu all over again" -- Yogi Berra



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RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Tony Hain
Margaret Wasserman wrote:
> Of course, in the case of site-local addresses, you don't 
> know for sure that you reached the _correct_ peer, unless you 
> know for sure that the node you want to reach is in your 
> site.  

Since the address block is ambiguous, routing will assure that if you
reach a node it is the correct one. This FUD needs to stop!

> So, when working from a list of addresses that 
> includes a site-local, an explicit refusal from the node that 
> you reach at the site-local address (i.e. connection reset, 
> port unreachable, or an application-level refusal) might not 
> be a reason to stop working down the list.

Your argument applies to global scope addresses, not ambiguous SL as
currently defined.

> 
> This is one case where the ambiguity of site-local addresses 
> causes problems that would not be caused by using addresses 
> that are globally unique, but unreachable.

It does not, routing explicitly breaks in the presence of ambiguous
addresses. That is the feature of ambiguity that many network managers
want. What others want and we haven't provided is a stable address block
that is unambiguous and unrelated to any providers they may be attached
to. 

> 
> I understand that a collision of site-local addresses will be 
> rare in autoconfigured networks.  But, in non-autoconfigured 
> networks, I'd still expect some proliferation of subnet == 1, 
> IID == 1.

This is not a problem, it is seen by many as a feature since it prevents
unintended exchange of routing information.

Tony 





RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Vernon Schryver
> From: "Christian Huitema" <[EMAIL PROTECTED]>

> ...
> Well, that is emphatically *NOT* what application developers do.

Speak for yourself.

> Which actually poses an interesting question: when should an application
> just give up? IMHO, there is only one clear-cut case, i.e. when the
> application actually contacted the peer and obtained an explicit
> statement that the planned exchange should not take place -- the
> equivalent of a 4XX or 5XX error in SMTP or HTTP. 

I've written application code that shuts up for a while when it
receives an errno value that indicates that the kernel has received
an ICMP Unreachable.

The code I'm thinking of is fairly portable, and so I've also had to
#ifdef it to ignore error numbers that ought to indicate an Unreachable
but don't on some UNIX-like systems or are not reported.


Vernon Schryver[EMAIL PROTECTED]



RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Jeroen Massar
Christian Huitema wrote:

> Well, that is emphatically *NOT* what application developers 
> do. They do not just observe that it does not work, they try
> to work around, e.g. routing messages to a different address,
> at a different time, through a third party, or through a
> different protocol. 

Indeed, correctly coded applications will use a getaddrinfo()
and then a connect() in a loop until succesful. This will
also overcome filtering as all possibilities will be tried
on the remote side. Note that 'succesful' here means that
it was able to setup a tcp connection. UDP is totally out
of the question here. Some applications could also modify
'succesful' to include a 2xx smtp reply etc. and absolute
failure to be defined by a 5xx error.

The problem is that this doesn't account for the locally-bound
IP though. Thus if a host has a 'site-local' and a 'global'
IP how does it know how to use which one?
Also note that getaddrinfo() is only in use since a couple
of years and most programmers are not even aware of it.

I would suggest that the applications never bind() to a
local address, this is possible for most applications.
Then the stack can figure out which address to use for
the outgoing connection. Most stacks will currently base
this on longest prefix matching. Thus if there is a 'local'
scope and the destination address is also in the same
'local' prefix, this address will be used for the connection.

Greets,
 Jeroen





RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Margaret Wasserman


Which actually poses an interesting question: when should an application
just give up? IMHO, there is only one clear-cut case, i.e. when the
application actually contacted the peer and obtained an explicit
statement that the planned exchange should not take place -- the
equivalent of a 4XX or 5XX error in SMTP or HTTP.
Of course, in the case of site-local addresses, you don't know for
sure that you reached the _correct_ peer, unless you know for
sure that the node you want to reach is in your site.  So, when
working from a list of addresses that includes a site-local, an
explicit refusal from the node that you reach at the site-local
address (i.e. connection reset, port unreachable, or an
application-level refusal) might not be a reason to stop working
down the list.
This is one case where the ambiguity of site-local addresses
causes problems that would not be caused by using addresses that
are globally unique, but unreachable.
I understand that a collision of site-local addresses will be
rare in autoconfigured networks.  But, in non-autoconfigured
networks, I'd still expect some proliferation of subnet == 1,
IID == 1.
Margaret






RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Jeroen Massar
Bill Manning wrote:

>   Is may be worth noting that RIRs have -NEVER- made presumptions
>   on routability of the delegations they make.

Did you just say 69/8 ? :)

If an ISP chooses not to make a specific prefix reachable
it is there 'problem'/policy, not much to do about it.

Also anybody could just start up a Registry where one can
register IP addresses for their "Cybernet" or whatever
they call it. No need to go to the RIR's. The addresses
won't be accepted by the Internet community though ;)

Greets,
 Jeroen




RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Christian Huitema
> > Applications will have to deal with that, yet there is no hint
> > unless we provide a well-known flag.
> 
> applications cannot be expected to deal with filters in any way other
than
> to report that the communication is prohibited.  the "well known" flag
> exists and is called ICMP.

Well, that is emphatically *NOT* what application developers do. They do
not just observe that it does not work, they try to work around, e.g.
routing messages to a different address, at a different time, through a
third party, or through a different protocol. 

Silently dropping packets is certainly not the right way to get an
application to stop trying. ICMP messages won't achieve that either:
since ICMP is insecure, it is routinely ignored.

Which actually poses an interesting question: when should an application
just give up? IMHO, there is only one clear-cut case, i.e. when the
application actually contacted the peer and obtained an explicit
statement that the planned exchange should not take place -- the
equivalent of a 4XX or 5XX error in SMTP or HTTP. 

-- Christian Huitema




Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Bill Manning
% >But suppose we really do have enough address space (independent of routing 
% >issues).  In that context, is site local just a shortcut to avoid dealing 
% >with a more general problem?  Should we have a address allocation policy 
% >that updates the policies of the 70s but ignores the intermediate "we are 
% >running out" steps? Should I be able to go to an RIR and ask for unique 
% >space for an isolated network, justify how much of it I need, and get it 
% >-- with no promises that the addresses can be routed (and, presumably, 
% >without pushing a wheelbarrow full of dollars/ euros/ yen/ won/ yuan/...)?
% 
% Yes, yes and yes.
% 
% Margaret

Is may be worth noting that RIRs have -NEVER- made presumptions
on routability of the delegations they make.

--bill
Opinions expressed may not even be mine by the time you read them, and
certainly don't reflect those of any other entity (legal or otherwise).



Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-31 Thread Margaret Wasserman
Hi John,

But suppose we really do have enough address space (independent of routing 
issues).  In that context, is site local just a shortcut to avoid dealing 
with a more general problem?  Should we have a address allocation policy 
that updates the policies of the 70s but ignores the intermediate "we are 
running out" steps? Should I be able to go to an RIR and ask for unique 
space for an isolated network, justify how much of it I need, and get it 
-- with no promises that the addresses can be routed (and, presumably, 
without pushing a wheelbarrow full of dollars/ euros/ yen/ won/ yuan/...)?
Yes, yes and yes.

Margaret







RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-28 Thread Michel Py
John,

> John C Klensin wrote:
> We, or more specifically, the upstream ISP or an RIR, can
> tell the ISP that things will go badly for them if they
> permit un-routable addresses to leak into the public
> Internet. The only difference I can see between what I
> think is your SL address preference and my "unique, but
> un-routable" one is that you would bind that advice/threat
> to a particular prefix while I would bind it to other
> indicators of "un-routable address". The reserved prefix
> approach is less likely to get mucked up by a clueless
> ISP, but I am unconvinced that we should make special
> architectural provisions to make it easier to be in the
> ISP business while being clueless.

I also think that policy alone can not enforce un-routability of
addresses. The only way to make sure that addresses are not routable on
the public Internet is to suppress the demand for routing them.

Example that works: RFC1918. Although we occasionally see these on the
public Internet, it's due to misconfiguration. No customer is going to
see their upstream and offer them money to leak or route RFC1918
addresses, because it achieves nothing (because RFC1918 addresses are
ambiguous). No demand, no routing.

Example that would not work: Allocate a block of regular addresses
(let's say, 2003::/16) to the purpose of globally unique non-routable
addresses. Whether you bind the advice/threat to that prefix to other
indicators of "un-routable address" you will create the demand from
end-sites to go to their providers and indeed ask them to route them to
be used as PI, with the result of routing table bloat.

What is required in order to get globally unique non-routable are three
things:
- Policy (the advice/threat).
- Some normative language mandating implementations (vs. policy)
  to disallow the practice (default blackholing).
- Some kind of architectural limitation such as site-local.

The combination of all three is required. The policy alone is not enough
because some ISPs will take the customer's money at the risk of being
labeled as bad boys. The normative language alone is not enough as we
have no way to force implementers to code it. The architectural
limitation alone is not enough as one will likely come up with a dirty
hack to route SLs globally if need be. Any combination of two would not
be a powerful enough deterrent either.

In other words: the only way to guarantee the non-routability of
globally unique private addresses is to put so many hurdles on the way
that it won't happen. To this effect, the proposed deprecation of
site-locals is a serious blow as it suppresses the architectural
limitation and therefore creates demand for sites to pay their ISPs to
"forget" to filter their prefixes and transform a non-routable globally
unique prefix into a de-facto routable globally unique prefix also
called PI.

Michel.




RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-28 Thread Tony Hain
John C Klensin wrote:
> ... but I am unconvinced that we should make special 
> architectural provisions to make it easier to be in the ISP 
> business while being clueless.

Isn't that just what we did with MPLS??  ;)
or does that just prove your point?  ;))

My arguments are more about acknowledging the reality and requirements
of the deployed architecture than they are about creating a special
case. Routing filters do and will exist, ergo local scope addresses will
exist. Applications will have to deal with that, yet there is no hint
unless we provide a well-known flag. I agree that applications should
not have to understand topology, but when they insist on passing around
topology information they have bought into the need to understand what
they are doing. DNS is one of the protocols that deals in topology
information, so it needs to understand topology. We need to make it
robust enough that applications can rely on it so they will simply pass
around names. 

In writing that it occurs to me that one of our failings is that we have
allowed a component of the system to have a very unrealistic (archaic)
view of what the network is. The DNS system is designed for the network
of 1985, and we blindly continue to use it as the database for locator
information in a very different network. I understand the IAB has
recently cleared its backlog of issues, so maybe this is a ripe topic
for them to address ...

Tony 




RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-28 Thread Tony Hain
John C Klensin wrote:
> (ii) ISPs impose restrictions on their customers all the time 
> and often even enforce them.  Many of us consider some of these 
> to be desirable (e.g., terms and conditions prohibiting 
> spamming) and others less so (e.g., prohibitions against running 
> server or peer-peer protocols over a cable network or address 
> restrictions that force reasonably-architected LANs into NAT 
> arrangements) but the conditions clearly exist.
> 

Note I said:
>>It is absolutely unreasonable for an ISP to tell their customer 
>>anything about running their network that is not directely 
>>related to the customer/provider interface. As long as the 
>>enterprise traffic over that interface is related to the 
>>capabilities they are paying for, it is none of the ISPs 
>>(or IETFs) business what they are doing elsewhere.

The ISPs do set terms for the customer/provider interface all the time,
and rightly so. They can not restrict me from setting up an 802.11 link
to my neighbor, only that my neighbor is not allowed to use that for
access to the provider's network. In a similar vein, the provider is not
in a position to tell customers what address space they can use for
purposes that do not interact with the provider interface. They can try,
and in a monopoly environment will probably succeed. That does not mean
we can tell ISPs to require that people not use any given address space
just because the provider is supplying another one. 

> I also note that site local addresses open up a whole series of 
> questions about "locality" and scope-range.  Perhaps we also 
> need "ISP-local" addresses (routing into one ISP's space, or 
> part of it, but not to that ISP's peers or transit customers) 
> and so on.  The one thing that can be guaranteed about that sort 
> of arrangement is an extension of the "pay enough and someone 
> will route it" model will apply: If some ISP sees a potential 
> competitive advantage in offering such a product (and 
> addresses), the product will follow soon thereafter.  And, 
> again, I think that this suggests that we had better figures out 
> how to deal with these things on a policy basis, not a 
> protocol-imbedded special address scope one.  We are almost 
> certain to have the policy problem anyway and it is not clear 
> that special cases for peculiar address scopes will buy us that 
> much in addition.

Address filtering exists in the network today, and will continue. Since
that is done as an expression of local policies, you are correct the
whole discussion is really about policy. It is not clear to me what the
IETF is in a position to do, other than define the operation of a
multifacited DNS. ;)

Tony 





RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-28 Thread Jeroen Massar
Bill Manning [mailto:[EMAIL PROTECTED] wrote:

> % David R. Oran wrote:
> % 
> % > Did anybody consider just handing out a /48 (or a bit smaller) 
> % > automagically with each DNS registration?
> % 
> % I proposed a couple of times a /32 from which /48 can be requested
> % for 'private' (never to be connected to the internet) purposes.
> % I think some others have proposed a similar thing. But the opposers
> % think that it won't be 'free' then... but they will be unique :)
> 
> Been there, Done it, Bought everything.
> SRInic was told to split the assignments into a
"connected/unconnected"
> database back in the day. It was ugly when folks figured that they
> really wanted to be connected and passed muster. renumbering was less
> fun in the late 1980s than today.
> Never want to re-introduce this concept unless/until we can get to the
> point of being able to painlessly renumber the entire Internet every
> 20 minutes.

That eliminates this 'solution'. History is bound to repeat
in these cases. Thus IMHO folks will just need to allocate
some random space or get it out some assigned space.

> Now where are those ""renumbering in IPv6 is easy" cookies.

Some other old stories made those crumble also :)
The renumbering isn't the part that is difficult, though it's
all the configuration items around it that's the burden.

Greets,
 Jeroen




Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-28 Thread Bill Manning
% David R. Oran wrote:
% 
% > Did anybody consider just handing out a /48 (or a bit smaller) 
% > automagically with each DNS registration?
% 
% I proposed a couple of times a /32 from which /48 can be requested
% for 'private' (never to be connected to the internet) purposes.
% I think some others have proposed a similar thing. But the opposers
% think that it won't be 'free' then... but they will be unique :)

Been there, Done it, Bought everything.
SRInic was told to split the assignments into a "connected/unconnected"
database back in the day. It was ugly when folks figured that they
really wanted to be connected and passed muster. renumbering was less
fun in the late 1980s than today.
Never want to re-introduce this concept unless/until we can get to the
point of being able to painlessly renumber the entire Internet every
20 minutes.  Now where are those ""renumbering in IPv6 is easy" cookies.


--bill
Opinions expressed may not even be mine by the time you read them, and
certainly don't reflect those of any other entity (legal or otherwise).



Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-28 Thread Bill Manning

 John, mixed bag of nasties here.  Routing, addressing, and (of course)
 the DNS.  More fun than should be legal on a friday afternoon.

 Routing: there is a varient here. Think about routing table slots.
 If I get one, does it matter what the length of the prefix that I
 put in it?   There are other abstraction methods besides aggregation,
 at least thats what some smart people are telling me.

 The other bits will have to wait.


%   * From an RIR, as PI space
%   
%   * From an ISP, as PD CIDR space.  ISPs might sensibly
%   decide to charge less (in money or aggravation) for
%   space which no one intended to route. Or might not: the
%   marketplace is good at sorting out these things, as long
%   as the RIRs are willing to make allocations to ISPs that
%   reflect the desirability of having addresses for
%   isolated networks unique and reflecting the ISPs to
%   which they might ultimately connect.
%   
%   * From some other process, as long-prefix, almost
%   certainly unroutable, isolated space.  This process
%   could presumably be designed to be very lightweight in
%   charges and administrative costs.
% 
% So, while I'm very hesitant about anything that ties addressing 
% (of any sort) to DNS names, I'm not convinced that Dave's 
% suggestion is worth dismissing out of hand.
% 
% Three additional observations:
% 
% (i) Tony's response to my note seems, to me, to turn SL largely 
% into a policy problem, not a technical one.  We haven't have 
% really good success binding policies into protocols.  That 
% doesn't convince me that we should never do so, but it does seem 
% to argue for looking at alternatives, even radical ones.
% 
% (ii) ISPs impose restrictions on their customers all the time 
% and often even enforce them.  Many of us consider some of these 
% to be desirable (e.g., terms and conditions prohibiting 
% spamming) and others less so (e.g., prohibitions against running 
% server or peer-peer protocols over a cable network or address 
% restrictions that force reasonably-architected LANs into NAT 
% arrangements) but the conditions clearly exist.
% 
% (iii) Yes, if I have an odd address and sufficient money, I can 
% almost certainly convince some ISP to route it.  But that ISP's 
% leverage to get its peers to accept any long-prefix addresses it 
% happens to offer and route them may be distinctly limited, 
% especially if, by offering/announcing those addresses, it is 
% violating a well-understood policy against doing such things. 
% (For example, an RIR policy that made PI address allocations 
% much more difficult for ISPs who were guilty of routing table 
% pollution by short prefixes could really focus the attention.) 
% So it seems to me to be plausible to suggest that the right 
% place to prevent routing table explosion (or even "bloat") is in 
% routing decisions and acceptance of announcements, and not in 
% creating special address scopes.
% 
% I also note that site local addresses open up a whole series of 
% questions about "locality" and scope-range.  Perhaps we also 
% need "ISP-local" addresses (routing into one ISP's space, or 
% part of it, but not to that ISP's peers or transit customers) 
% and so on.  The one thing that can be guaranteed about that sort 
% of arrangement is an extension of the "pay enough and someone 
% will route it" model will apply: If some ISP sees a potential 
% competitive advantage in offering such a product (and 
% addresses), the product will follow soon thereafter.  And, 
% again, I think that this suggests that we had better figures out 
% how to deal with these things on a policy basis, not a 
% protocol-imbedded special address scope one.  We are almost 
% certain to have the policy problem anyway and it is not clear 
% that special cases for peculiar address scopes will buy us that 
% much in addition.
% 
%john
% 
% 


-- 
--bill

Opinions expressed may not even be mine by the time you read them, and
certainly don't reflect those of any other entity (legal or otherwise).




RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-28 Thread Jeroen Massar
David R. Oran wrote:

> Did anybody consider just handing out a /48 (or a bit smaller) 
> automagically with each DNS registration?

I proposed a couple of times a /32 from which /48 can be requested
for 'private' (never to be connected to the internet) purposes.
I think some others have proposed a similar thing. But the opposers
think that it won't be 'free' then... but they will be unique :)

Greets,
 Jeroen




Re: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-28 Thread Valdis . Kletnieks
On Fri, 28 Mar 2003 14:00:31 EST, "David R. Oran" said:
> Did anybody consider just handing out a /48 (or a bit smaller) 
> automagically with each DNS registration?

Routing Table Bloat.  If you can figure out how to do this in a CIDR
aggregation context, or otherwise work around the table problem, the
IETF and NANOG will quite certainly jointly nominate you for sainthood. ;)


pgp0.pgp
Description: PGP signature


RE: Thinking differently about the site local problem (was: RE: site local addresses (was Re: Fw: Welcome to the InterNAT...))

2003-03-28 Thread Tony Hain
John C Klensin wrote:
> Tony,
> 
> I've been trying to get my mind around the various issues here, 
> and I keep getting back to the same place, so I think I need to 
> embarrass myself by making a proposal that I find frightening.
> 
> Let's assume, as I think you have suggested, that SL is all 
> about local addresses and filtering, and not about some special 
> prefix that applications need to recognize.  I'm still not sure 
> I believe that, but let's assume it is true and see where that 
> takes us.
> 
> Let's also remember the long path that got us to CIDR and 1918. 
> Our original position was that anyone using TCP/IP (v4) should 
> have unique address space.  I remember many discussions in which 
> people were told "don't just grab an address on the theory that 
> you would never connect. Our experience has been that, sooner or 
> later, you might connect to the public network, or connect to 
> someone else who has used 'private' (or 'squatter') space... 
> unique addresses will save you, and everyone else, a lot of 
> trouble".  In that context, 1918 and its predecessors came out 
> of two threads of developments:
> 
>   * we were running short of addresses and wanted to
>   discourage unconnected (or hidden) networks from using
>   up public space and
>   
>   * we hoped that, by encouraging such isolated networks
>   to use some specific address ranges, those ranges could
>   be easily and effectively filtered at the boundaries.
> 
> We can debate how well either really worked, or what nasty 
> side-effects they caused, but probably it makes little 
> difference in the last analysis except to note that, no matter 
> what we do, leaks happen.
> 
> Now one of the problems IPv6 was supposed to solve was "too 
> little address space" or, more specifically, our having to make 
> architecturally bad decisions on the basis of address space 
> exhaustion.  I hope we have solved it.  If we haven't, i.e., if 
> the address space is still too small, then the time to deal with 
> that issue is right now (or sooner), before IPv6 is more broadly 
> deployed (and it better be variable-length the next time, 
> because, if we are conceptually running short of space already, 
> it would be, IMO, conclusive proof that we have no idea how to 
> specify X in "X addresses will be enough").
> 
> But suppose we really do have enough address space (independent 
> of routing issues).  In that context, is site local just a 
> shortcut to avoid dealing with a more general problem?  Should 
> we have a address allocation policy that updates the policies of 
> the 70s but ignores the intermediate "we are running out" steps? 
> Should I be able to go to an RIR and ask for unique space for an 
> isolated network, justify how much of it I need, and get it -- 
> with no promises that the addresses can be routed (and, 
> presumably, without pushing a wheelbarrow full of dollars/ 
> euros/ yen/ won/ yuan/...)?

The problems with this theory are that a registry costs money to run,
and it requires an organization to expose their business plan (never
mind figuring out who is really qualified to judge the validity of any
given justification). Even when the big bad US Gov. was picking up the
tab, there were cost control measures that required someone to validate
the request (I was one such sanity checker). If we create a space that
requires registration, it will become a simple -biggest wallet gets the
most space- arrangement, because it is in the financial interest of the
registry to accept all requests. The only push back to that is to set
the price per prefix high enough that the registry doesn't need more
cash to run, but that, and the recurring nature of those costs, will
cause people to avoid the registry and use random numbers. The other
point in this is that you can't force people to register until there is
a technical reason for it, like making routing work. 

> 
> Of course, this takes us fairly far onto the path of having to 
> think about multihomed hosts, not just multihomed LANs, but, as 
> others have pointed out, the notion of multiple addresses (or 
> multiple prefixes) for a given host (or interface) takes us 
> rather far down that path anyway.  Figuring out which address to 
> use is a problem we need to solve, with or without SL, or the 
> whole idea of multiple addresses on hosts, especially dumb 
> hosts, is going to turn out to be a non-starter.  And, as Louis, 
> Noel, and others have pointed out, it is hard.   But, if we can 
> find a solution, even one that is just mostly locally-optimal 
> and that fails occasionally, then it seems to me that your 
> position ultimately gives no advantages to a reserved site-local 
> form over unique, but non-routable, addresses.  The advantages 
> of the latter appear obvious, starting with being able to 
> identify the sources of address leaks and the notion that 
> routability is a separate negotiation with providers (and their 
> peers and oth