Re: teredo.ipv6.microsoft.com off?

2013-07-19 Thread Marco Sommani
On 18/lug/2013, at 22:09, Brian E Carpenter brian.e.carpen...@gmail.com wrote:

 Wait... I had the impression that iff there was no other IPv6 connectivity,
 Teredo was used in older Windows because of the generic prefer IPv6 rule.
 The default RFC 3484 table covers 6to4 but not Teredo.
 
 Recent Windows deprefs Teredo of course.
 
   Brian

Right. The policy table in RFC 3484 has no specific entry for prefix 2001::/32. 
This is corrected in the table of RFC 6724:

  PrefixPrecedence Label
  ::1/128   50 0
  ::/0  40 1
  :::0:0/96 35 4
  2002::/16 30 2
  2001::/32  5 5
  fc00::/7   313
  ::/96  1 3
  fec0::/10  111
  3ffe::/16  112

-- 
Marco Sommani
Consiglio Nazionale delle Ricerche
Istituto di Informatica e Telematica
Via Giuseppe Moruzzi 1
56124 Pisa - Italia
work: +390506212127
mobile: +393487981019 
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Re: teredo.ipv6.microsoft.com off?

2013-07-19 Thread Martin Millnert
On 19 jul 2013, at 11:30, Marco Sommani marco.somm...@iit.cnr.it wrote:

 On 18/lug/2013, at 22:09, Brian E Carpenter brian.e.carpen...@gmail.com 
 wrote:
 
 Wait... I had the impression that iff there was no other IPv6 connectivity,
 Teredo was used in older Windows because of the generic prefer IPv6 rule.
 The default RFC 3484 table covers 6to4 but not Teredo.
 
 Recent Windows deprefs Teredo of course.
 
  Brian
 
 Right. The policy table in RFC 3484 has no specific entry for prefix 
 2001::/32. This is corrected in the table of RFC 6724:
 
  PrefixPrecedence Label
  ::1/128   50 0
  ::/0  40 1
  :::0:0/96 35 4
  2002::/16 30 2
  2001::/32  5 5
  fc00::/7   313
  ::/96  1 3
  fec0::/10  111
  3ffe::/16  112
 

From what I recall from MS representatives, gethostbyname() etc does not send 
 queries, if nothing better is configured.  Would this be controlled by 
the table above (6724)?

/Martin - (native v6 FTW)

Re: teredo.ipv6.microsoft.com off?

2013-07-19 Thread Marco Sommani
On 19/lug/2013, at 10:50, Martin Millnert mar...@millnert.se wrote:

 On 19 jul 2013, at 11:30, Marco Sommani marco.somm...@iit.cnr.it wrote:
 
 On 18/lug/2013, at 22:09, Brian E Carpenter brian.e.carpen...@gmail.com 
 wrote:
 
 Wait... I had the impression that iff there was no other IPv6 connectivity,
 Teredo was used in older Windows because of the generic prefer IPv6 rule.
 The default RFC 3484 table covers 6to4 but not Teredo.
 
 Recent Windows deprefs Teredo of course.
 
 Brian
 
 Right. The policy table in RFC 3484 has no specific entry for prefix 
 2001::/32. This is corrected in the table of RFC 6724:
 
 PrefixPrecedence Label
 ::1/128   50 0
 ::/0  40 1
 :::0:0/96 35 4
 2002::/16 30 2
 2001::/32  5 5
 fc00::/7   313
 ::/96  1 3
 fec0::/10  111
 3ffe::/16  112
 
 
 From what I recall from MS representatives, gethostbyname() etc does not send 
  queries, if nothing better is configured.  Would this be controlled by 
 the table above (6724)?
 
 /Martin - (native v6 FTW)


If I understand the RFC correctly,  queries are sent anyway, but, if in the 
end the choice is between using the IPv4 source address or the Teredo source 
address, the IPv4 source is preferred, because its entry in the table (prefix 
:::0:0/96) has a greater precedence (35) than the Teredo prefix (5). The 
choice of the IPv4 source address has, as a consequence, tha fact that the 
destination address must be IPv4 too, so the  record is ignored, even if it 
was returned by the DNS query.

-- 
Marco Sommani
Consiglio Nazionale delle Ricerche
Istituto di Informatica e Telematica
Via Giuseppe Moruzzi 1
56124 Pisa - Italia
work: +390506212127
mobile: +393487981019 
fax: +390503158327
mailto:marco.somm...@iit.cnr.it



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Re: teredo.ipv6.microsoft.com off?

2013-07-19 Thread Phil Mayers

On 07/18/2013 09:09 PM, Brian E Carpenter wrote:


Wait... I had the impression that iff there was no other IPv6 connectivity,
Teredo was used in older Windows because of the generic prefer IPv6 rule.
The default RFC 3484 table covers 6to4 but not Teredo.


AFAIK, every version of windows (i.e. Vista, 7, 8) that comes with 
Teredo also comes with a de-pref rule for it, not just recent versions.


Put another way, Teredo should never be preferred over IPv4, because all 
versions of Windows with Teredo use extended RFC 3484 rules.


Most of the Teredo activity we see is when IP addresses are used 
directly (i.e. no getaddrinfo). For example, BitTorrent connections 
where peers were looked up in DHT/PEX. In these cases, an IPv6 address 
will be connected to over Teredo if there's no other connectivity.


Re: teredo.ipv6.microsoft.com off?

2013-07-19 Thread Tim Chown

On 19 Jul 2013, at 10:34, Phil Mayers p.may...@imperial.ac.uk wrote:

 On 07/18/2013 09:09 PM, Brian E Carpenter wrote:
 
 Wait... I had the impression that iff there was no other IPv6 connectivity,
 Teredo was used in older Windows because of the generic prefer IPv6 rule.
 The default RFC 3484 table covers 6to4 but not Teredo.
 
 AFAIK, every version of windows (i.e. Vista, 7, 8) that comes with Teredo 
 also comes with a de-pref rule for it, not just recent versions.
 
 Put another way, Teredo should never be preferred over IPv4, because all 
 versions of Windows with Teredo use extended RFC 3484 rules.
 
 Most of the Teredo activity we see is when IP addresses are used directly 
 (i.e. no getaddrinfo). For example, BitTorrent connections where peers were 
 looked up in DHT/PEX. In these cases, an IPv6 address will be connected to 
 over Teredo if there's no other connectivity.

Again, my understanding is the same as Phil's here.

Many vendors/implementors started adding rules that ultimately appeared in 
RFC6724 long before RFC6724 was published.  It took 6 years(!) for that update 
to be completed through the IETF.   

There are however some platforms stuck on 3484 or that don't follow such rules 
(Mac OSX is an interesting one...)

Tim



Re: teredo.ipv6.microsoft.com off?

2013-07-19 Thread Brian E Carpenter
On 19/07/2013 22:15, Tim Chown wrote:
 On 19 Jul 2013, at 10:34, Phil Mayers p.may...@imperial.ac.uk wrote:
 
 On 07/18/2013 09:09 PM, Brian E Carpenter wrote:

 Wait... I had the impression that iff there was no other IPv6 connectivity,
 Teredo was used in older Windows because of the generic prefer IPv6 rule.
 The default RFC 3484 table covers 6to4 but not Teredo.
 AFAIK, every version of windows (i.e. Vista, 7, 8) that comes with Teredo 
 also comes with a de-pref rule for it, not just recent versions.

 Put another way, Teredo should never be preferred over IPv4, because all 
 versions of Windows with Teredo use extended RFC 3484 rules.

 Most of the Teredo activity we see is when IP addresses are used directly 
 (i.e. no getaddrinfo). For example, BitTorrent connections where peers were 
 looked up in DHT/PEX. In these cases, an IPv6 address will be connected to 
 over Teredo if there's no other connectivity.
 
 Again, my understanding is the same as Phil's here.

I think my recollection is of Teredo with Windows XP SP2. But I
could be wrong, of course. In any case, the case for phasing out
Teredo is strong, like the case for disabling client-side 6to4.

   Brian

 Many vendors/implementors started adding rules that ultimately appeared in 
 RFC6724 long before RFC6724 was published.  It took 6 years(!) for that 
 update to be completed through the IETF.   
 
 There are however some platforms stuck on 3484 or that don't follow such 
 rules (Mac OSX is an interesting one...)
 
 Tim
 
 


Re: teredo.ipv6.microsoft.com off?

2013-07-18 Thread Martin Millnert


On 17 jul 2013, at 23:09, Brian E Carpenter brian.e.carpen...@gmail.com wrote:

 On 17/07/2013 19:13, Ignatios Souvatzis wrote:
 ...
 
 Let me ask one thing... a couple of years ago, when I read the
 specification of Teredo, I was quite impressed by the details (If
 you accept the premise that you have to work around being jailed
 behind an IPv4 NAT) put into the protocol. One detail was that it
 is supposed to be lowest priority and so go automatically away
 (from the client end) as soon as some configued IPv6 is available
 on the link.
 
 Isn't that how it's implemented?
 
 Yes, but the result is that the host tries to use Teredo preferentially
 even if the IPv4 path is better; and if the Teredo path is broken
 the result is user pain (as with 6to4). I think the idea of deprecating
 Teredo is that now that native IPv6 is a serious option, the costs of
 Teredo outweigh the benefits,on average.
 
 (Unfortunately nobody ever wrote the Teredo equivalent of RFC6343.)
 
Brian

When connecting to IPv6 literals, it will use IPv6, yes.
It wont resolve s for IPv6 connection using Teredo.

This used to be the facts and big difference between Teredo and 6to4 and I 
would be surprised if that has changed.

martin

Re: teredo.ipv6.microsoft.com off?

2013-07-18 Thread Phil Mayers

On 17/07/13 21:09, Brian E Carpenter wrote:

On 17/07/2013 19:13, Ignatios Souvatzis wrote:
...


Let me ask one thing... a couple of years ago, when I read the
specification of Teredo, I was quite impressed by the details (If
you accept the premise that you have to work around being jailed
behind an IPv4 NAT) put into the protocol. One detail was that it
is supposed to be lowest priority and so go automatically away
(from the client end) as soon as some configued IPv6 is available
on the link.

Isn't that how it's implemented?


Yes, but the result is that the host tries to use Teredo preferentially
even if the IPv4 path is better; and if the Teredo path is broken


That is the opposite of how it's supposed to work. Teredo addresses 
should be de-pref'd below everything else, and would thus only be used 
for connection to IPv6-only hosts if the host lacked other IPv6 
connectivity.


As someone else has pointed out, maybe it gets used for IPv6 literals, 
but not hostnames - the RFC 3484 table on windows ensures this.


Re: teredo.ipv6.microsoft.com off?

2013-07-18 Thread Tim Chown
On 18 Jul 2013, at 11:29, Phil Mayers p.may...@imperial.ac.uk wrote:

 On 17/07/13 21:09, Brian E Carpenter wrote:
 On 17/07/2013 19:13, Ignatios Souvatzis wrote:
 ...
 
 Let me ask one thing... a couple of years ago, when I read the
 specification of Teredo, I was quite impressed by the details (If
 you accept the premise that you have to work around being jailed
 behind an IPv4 NAT) put into the protocol. One detail was that it
 is supposed to be lowest priority and so go automatically away
 (from the client end) as soon as some configued IPv6 is available
 on the link.
 
 Isn't that how it's implemented?
 
 Yes, but the result is that the host tries to use Teredo preferentially
 even if the IPv4 path is better; and if the Teredo path is broken
 
 That is the opposite of how it's supposed to work. Teredo addresses should be 
 de-pref'd below everything else, and would thus only be used for connection 
 to IPv6-only hosts if the host lacked other IPv6 connectivity.
 
 As someone else has pointed out, maybe it gets used for IPv6 literals, but 
 not hostnames - the RFC 3484 table on windows ensures this.

Indeed; that's how it *should* be.

Tim



Re: teredo.ipv6.microsoft.com off?

2013-07-17 Thread Ignatios Souvatzis
Hello,

On Tue, Jul 16, 2013 at 09:27:54PM +, Christopher Palmer wrote:
 I am acking this thread.
 
 If there is feedback on the ongoing experiment or our consideration
 of sunsetting Teredo, do let me know.
 
 So far people have been quite enthusiastic. 

Let me ask one thing... a couple of years ago, when I read the
specification of Teredo, I was quite impressed by the details (If
you accept the premise that you have to work around being jailed
behind an IPv4 NAT) put into the protocol. One detail was that it
is supposed to be lowest priority and so go automatically away
(from the client end) as soon as some configued IPv6 is available
on the link.

Isn't that how it's implemented?

Regards,
-is


Re: teredo.ipv6.microsoft.com off?

2013-07-17 Thread Jeroen Massar
On 2013-07-17 15:09 , Ron Broersma wrote:
 
 On Jul 16, 2013, at 10:40 PM, Mikael Abrahamsson wrote:
 
 On Tue, 16 Jul 2013, Christopher Palmer wrote:
 
 If there is feedback on the ongoing experiment or our
 consideration of sunsetting Teredo, do let me know.
 
 So far people have been quite enthusiastic.
 
 I am too. I would really like to see 6to4 and teredo be default off
 everywhere, and people who want it can manually turn it on. If
 teredo went away completely, that would also be a good thing.
 
 Strongly concur here as well.  One less thing I have to disable on
 all my systems in enterprise nets.

Windows boxes that are in an Active Domain (which should match your
'enterprise net') have Teredo and 6to4 disabled per default.

Next to that one can enforce that of course through AD policies.

Greets,
 Jeroen


Re: teredo.ipv6.microsoft.com off?

2013-07-17 Thread Jens Link
Jeroen Massar jer...@massar.ch writes:

 Windows boxes that are in an Active Domain (which should match your
 'enterprise net') have Teredo and 6to4 disabled per default.

Sure about that? IIRC this depends on the Windows version. And I think I
have seen Win 2008R2 Servers within an AD, with at least 6to4
enable. Right now I'm not sure about Teredo. 

 Next to that one can enforce that of course through AD policies.

Okay, not a group policies, but for reference: 

http://lists.cluenet.de/pipermail/ipv6-ops/2010-March/003267.html

Where are the Windows people on this list? ;-) 

Jens
-- 
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| Foelderichstr. 40   | 13595 Berlin, Germany| +49-151-18721264 |
| http://blog.quux.de | jabber: jensl...@guug.de | ---  | 
-


Re: teredo.ipv6.microsoft.com off?

2013-07-17 Thread Enno Rey
Ron,

  I am too. I would really like to see 6to4 and teredo be default off
  everywhere, and people who want it can manually turn it on. If
  teredo went away completely, that would also be a good thing.
  
  Strongly concur here as well.  One less thing I have to disable on
  all my systems in enterprise nets.
  
  Windows boxes that are in an Active Domain (which should match your
  'enterprise net') have Teredo and 6to4 disabled per default.
  Next to that one can enforce that of course through AD policies.
 
 A number of my enterprise nets support many OSs and are not AD-centric.  
 That's why I qualified my enterprise nets as heterogeneous.  But yes, if 
 you are homogeneous on Windows and everything is in AD, you can disable those 
 things through GPO.  For me, we have to tell each of our users to disable 
 teredo, disable 6to4, disable privacy/temporary addresses, etc., and in many 
 cases beg them to upgrade to OSs that support DHCPv6.
 

what if they use Android based systems? is there support for DHCPv6 in the 
interim?

best

Enno






-- 
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Re: teredo.ipv6.microsoft.com off?

2013-07-17 Thread Enno Rey
Hi,

off the top of my head it's roughly as follows:

a) 6to4

Win7/Server 2008 generation and before: if IPv4 address = Non-RFC 1918 
address, automatically enable 6to4 and try to resolve 6to4.ipv6.microsoft.com 
to get 'nearest relay'.

no idea as for Win8/Server 2012.

b) Teredo

Vista: enable by default.
Win7/Server 2008: perform the following decision logic:

1) if $SYSTEM member of AD domain, assume that $SYSTEM is well managed = no 
need for SOHO tech called Teredo, hence disable it.
2) if $SYSTEM does _not_ have local firewall enabled, assume that $SYSTEM in 
poor security state and it might be too risky to use Teredo, hence disable it.
3) if both above conditions _not_ met (read: not member of AD domain, but local 
firewall enabled), then put Teredo into 'dormant' state and try to reach 
teredo.ipv6.microsoft.com every 30 seconds to check if Teredo usable if needed.
once $APPLICATION asks for that, move from 'dormant' into 'qualified' state and 
thereby 'enable' Teredo.

again, no idea as for Win8/Server 2012. 

I can't support the above statements by any links, right now.
Maybe Chris Palmer can help with that...

Furthermore there's different ways of getting rid of Teredo (and the other 
tunnel techs):
- there's a registry parameter 'DisabledComponents' that allows disabling 
(native|tunnel|all) IPv6, based on a certain bit mask. see KB929852.
- (presumably) this parameter can be controlled by GPOs.
- the tunnel interfaces can be disabled individually by netsh int $TUNNEL_INT 
set state disabled on individual systems (persistently, so setting stays after 
reboot).

There's quite some debate which approach to use due to operational practices 
and MS telling people not to 'fully' disable IPv6 as you might lose support 
for $SYSTEM. I've never been able to find any 'official source' for the latter 
statement but heard it in pretty much all enterprise environments (our Windows 
people tell us we can't do that as the MS engineers tell them they will lose 
support then).




best

Enno




On Wed, Jul 17, 2013 at 03:36:00PM +0200, Jens Link wrote:
 Jeroen Massar jer...@massar.ch writes:
 
  Windows boxes that are in an Active Domain (which should match your
  'enterprise net') have Teredo and 6to4 disabled per default.
 
 Sure about that? IIRC this depends on the Windows version. And I think I
 have seen Win 2008R2 Servers within an AD, with at least 6to4
 enable. Right now I'm not sure about Teredo. 
 
  Next to that one can enforce that of course through AD policies.
 
 Okay, not a group policies, but for reference: 
 
 http://lists.cluenet.de/pipermail/ipv6-ops/2010-March/003267.html
 
 Where are the Windows people on this list? ;-) 
 
 Jens
 -- 
 -
 | Foelderichstr. 40   | 13595 Berlin, Germany| +49-151-18721264 |
 | http://blog.quux.de | jabber: jensl...@guug.de | ---  | 
 -

-- 
Enno Rey

ERNW GmbH - Carl-Bosch-Str. 4 - 69115 Heidelberg - www.ernw.de
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Handelsregister Mannheim: HRB 337135
Geschaeftsfuehrer: Enno Rey

Troopers 2013 Videos online: 
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RE: teredo.ipv6.microsoft.com off?

2013-07-17 Thread Eric Vyncke (evyncke)
Jeroen

AFAIK, only Teredo is disabled when the Windows host detects AD

-éric

 -Original Message-
 From: ipv6-ops-bounces+evyncke=cisco@lists.cluenet.de [mailto:ipv6-ops-
 bounces+evyncke=cisco@lists.cluenet.de] On Behalf Of Jeroen Massar
 Sent: mercredi 17 juillet 2013 15:20
 To: Ron Broersma
 Cc: Christopher Palmer; ipv6-ops@lists.cluenet.de; Mikael Abrahamsson
 Subject: Re: teredo.ipv6.microsoft.com off?
 
 On 2013-07-17 15:09 , Ron Broersma wrote:
 
  On Jul 16, 2013, at 10:40 PM, Mikael Abrahamsson wrote:
 
  On Tue, 16 Jul 2013, Christopher Palmer wrote:
 
  If there is feedback on the ongoing experiment or our consideration
  of sunsetting Teredo, do let me know.
 
  So far people have been quite enthusiastic.
 
  I am too. I would really like to see 6to4 and teredo be default off
  everywhere, and people who want it can manually turn it on. If teredo
  went away completely, that would also be a good thing.
 
  Strongly concur here as well.  One less thing I have to disable on all
  my systems in enterprise nets.
 
 Windows boxes that are in an Active Domain (which should match your
 'enterprise net') have Teredo and 6to4 disabled per default.
 
 Next to that one can enforce that of course through AD policies.
 
 Greets,
  Jeroen


Re: teredo.ipv6.microsoft.com off?

2013-07-17 Thread Ron Broersma

On Jul 17, 2013, at 6:20 AM, Jeroen Massar wrote:

 On 2013-07-17 15:09 , Ron Broersma wrote:
 
 On Jul 16, 2013, at 10:40 PM, Mikael Abrahamsson wrote:
 
 On Tue, 16 Jul 2013, Christopher Palmer wrote:
 
 If there is feedback on the ongoing experiment or our
 consideration of sunsetting Teredo, do let me know.
 
 So far people have been quite enthusiastic.
 
 I am too. I would really like to see 6to4 and teredo be default off
 everywhere, and people who want it can manually turn it on. If
 teredo went away completely, that would also be a good thing.
 
 Strongly concur here as well.  One less thing I have to disable on
 all my systems in enterprise nets.
 
 Windows boxes that are in an Active Domain (which should match your
 'enterprise net') have Teredo and 6to4 disabled per default.
 Next to that one can enforce that of course through AD policies.

A number of my enterprise nets support many OSs and are not AD-centric.  That's 
why I qualified my enterprise nets as heterogeneous.  But yes, if you are 
homogeneous on Windows and everything is in AD, you can disable those things 
through GPO.  For me, we have to tell each of our users to disable teredo, 
disable 6to4, disable privacy/temporary addresses, etc., and in many cases beg 
them to upgrade to OSs that support DHCPv6.



smime.p7s
Description: S/MIME cryptographic signature


Re: teredo.ipv6.microsoft.com off?

2013-07-17 Thread Jens Link
Jens Link li...@quux.de writes:

as I like to talk to myself 

 There's quite some debate which approach to use due to operational
 practices and MS telling people not to 'fully' disable IPv6 as you
 might lose support for $SYSTEM. 

 I'm still looking for a source too. 

http://technet.microsoft.com/en-us/network/cc987595.aspx

(Q. What are Microsoft's recommendations about disabling IPv6?)

I'm not sure if that is official enough or not.

Jens
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| http://blog.quux.de | jabber: jensl...@guug.de | ---  | 
-


Re: teredo.ipv6.microsoft.com off?

2013-07-17 Thread Ron Broersma
 There's quite some debate which approach to use due to operational
 practices and MS telling people not to 'fully' disable IPv6 as you
 might lose support for $SYSTEM. 
 
 I'm still looking for a source too. Rumors have it that the Windows 7
 roll out here (large enterprise customer) will be with IPv6 disabled. I
 guess that why they hired me to do the IPv6 planing (on the network
 side).

Most of the talks that I've seen from Sean Siler (IPv6 guy at Microsoft) have a 
slide on best practices, where his point #1 is Leave Windows in the default 
configuration (IPv6 enabled), and he describes how disabling IPv6 comes with 
risk because you will be operating the OS in an untested configuration.  We 
translate that into a security issue, and therefore make is a security 
violation to disable IPv6 in Windows7 and later.  I know that is somewhat 
inconsistent with the DoD STIG, but IMHO the STIG is wrong.



smime.p7s
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Re: teredo.ipv6.microsoft.com off?

2013-07-17 Thread Jens Link
Enno Rey e...@ernw.de writes:

Hi,

 There's quite some debate which approach to use due to operational
 practices and MS telling people not to 'fully' disable IPv6 as you
 might lose support for $SYSTEM. 

I'm still looking for a source too. Rumors have it that the Windows 7
roll out here (large enterprise customer) will be with IPv6 disabled. I
guess that why they hired me to do the IPv6 planing (on the network
side).

Disabling IPv6 will lead to some problems: 

http://support.microsoft.com/kb/2549656 

(DNS Server service randomly cannot resolve external names and returns a
Server Failure error if IPv6 is disabled in Windows Server 2008 and
Windows Server 2008 R2)

This is an actual problem for a customer where I helped implementing
IPv6 last year. They dont use Windows but they are running a large dual
stacked website. 

Jens
-- 
-
| Foelderichstr. 40   | 13595 Berlin, Germany| +49-151-18721264 |
| http://blog.quux.de | jabber: jensl...@guug.de | ---  | 
-


Re: teredo.ipv6.microsoft.com off?

2013-07-17 Thread Enno Rey
Hi,

thanks for that link.
big questions is: what means disabling IPv6 in those contexts?
unchecking IPv6 in GUI based interface properties? setting DisabledComponents 
to 0xfff? using some netsh-based approach?

from what I hear: as long as you can successfully ping ::1, IPv6 is considered 
enabled and MS regards this as a 'supported configuration'.

best

Enno



On Wed, Jul 17, 2013 at 04:45:58PM +0200, Jens Link wrote:
 Enno Rey e...@ernw.de writes:
 
 Hi,
 
  There's quite some debate which approach to use due to operational
  practices and MS telling people not to 'fully' disable IPv6 as you
  might lose support for $SYSTEM. 
 
 I'm still looking for a source too. Rumors have it that the Windows 7
 roll out here (large enterprise customer) will be with IPv6 disabled. I
 guess that why they hired me to do the IPv6 planing (on the network
 side).
 
 Disabling IPv6 will lead to some problems: 
 
 http://support.microsoft.com/kb/2549656 
 
 (DNS Server service randomly cannot resolve external names and returns a
 Server Failure error if IPv6 is disabled in Windows Server 2008 and
 Windows Server 2008 R2)
 
 This is an actual problem for a customer where I helped implementing
 IPv6 last year. They dont use Windows but they are running a large dual
 stacked website. 
 
 Jens
 -- 
 -
 | Foelderichstr. 40   | 13595 Berlin, Germany| +49-151-18721264 |
 | http://blog.quux.de | jabber: jensl...@guug.de | ---  | 
 -

-- 
Enno Rey

ERNW GmbH - Carl-Bosch-Str. 4 - 69115 Heidelberg - www.ernw.de
Tel. +49 6221 480390 - Fax 6221 419008 - Cell +49 174 3082474
PGP FP 055F B3F3 FE9D 71DD C0D5  444E C611 033E 3296 1CC1

Handelsregister Mannheim: HRB 337135
Geschaeftsfuehrer: Enno Rey

Troopers 2013 Videos online: 
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Re: teredo.ipv6.microsoft.com off?

2013-07-17 Thread Brian E Carpenter
On 17/07/2013 19:13, Ignatios Souvatzis wrote:
...

 Let me ask one thing... a couple of years ago, when I read the
 specification of Teredo, I was quite impressed by the details (If
 you accept the premise that you have to work around being jailed
 behind an IPv4 NAT) put into the protocol. One detail was that it
 is supposed to be lowest priority and so go automatically away
 (from the client end) as soon as some configued IPv6 is available
 on the link.
 
 Isn't that how it's implemented?

Yes, but the result is that the host tries to use Teredo preferentially
even if the IPv4 path is better; and if the Teredo path is broken
the result is user pain (as with 6to4). I think the idea of deprecating
Teredo is that now that native IPv6 is a serious option, the costs of
Teredo outweigh the benefits,on average.

(Unfortunately nobody ever wrote the Teredo equivalent of RFC6343.)

Brian


RE: teredo.ipv6.microsoft.com off?

2013-07-16 Thread Christopher Palmer
I am acking this thread.

If there is feedback on the ongoing experiment or our consideration of 
sunsetting Teredo, do let me know.

So far people have been quite enthusiastic. 


-
christopher.pal...@microsoft.com
Windows Networking Core - Program Manager
Core Client Connectivity and Protocols


-Original Message-
From: ipv6-ops-bounces+christopher.palmer=microsoft@lists.cluenet.de 
[mailto:ipv6-ops-bounces+christopher.palmer=microsoft@lists.cluenet.de] On 
Behalf Of Ignatios Souvatzis
Sent: Sunday, July 14, 2013 11:52 PM
To: ipv6-ops@lists.cluenet.de
Subject: Re: teredo.ipv6.microsoft.com off?

On Sat, Jul 13, 2013 at 10:39:12PM +0300, Tassos Chatzithomaoglou wrote:

 At the same time, i'm thinking out loud...
 Why would a windows application send an a request to an IPv6 DNS 
 server over native IPv6 in order to find the IPv4 address of a server 
 and get IPv6 over IPv4 connectivity?

Why not? Thinking in order to is wrong... it's just a database lookup.

It just happens that in this case, asking over IPv6 can't work.
But this should be no problem as the database lookup will be repeated over 
other transports until it succeeds.

In the general case, you don't know whether connectivity to address X of type Y 
is possible until you try it, and unfortunately, sometimes only after a 
time-out period has passed without answer. 

Regards,
-is





RE: teredo.ipv6.microsoft.com off?

2013-07-16 Thread Mikael Abrahamsson

On Tue, 16 Jul 2013, Christopher Palmer wrote:

If there is feedback on the ongoing experiment or our consideration of 
sunsetting Teredo, do let me know.


So far people have been quite enthusiastic.


I am too. I would really like to see 6to4 and teredo be default off 
everywhere, and people who want it can manually turn it on. If teredo went 
away completely, that would also be a good thing.


--
Mikael Abrahamssonemail: swm...@swm.pp.se


Re: teredo.ipv6.microsoft.com off?

2013-07-15 Thread Ignatios Souvatzis
On Sat, Jul 13, 2013 at 10:39:12PM +0300, Tassos Chatzithomaoglou wrote:

 At the same time, i'm thinking out loud...
 Why would a windows application send an a request to an IPv6 DNS
 server over native IPv6 in order to find the IPv4 address of a
 server and get IPv6 over IPv4 connectivity?

Why not? Thinking in order to is wrong... it's just a database
lookup.

It just happens that in this case, asking over IPv6 can't work.
But this should be no problem as the database lookup will be repeated
over other transports until it succeeds.

In the general case, you don't know whether connectivity to address X of
type Y is possible until you try it, and unfortunately, sometimes only 
after a time-out period has passed without answer. 

Regards,
-is


Re: teredo.ipv6.microsoft.com off?

2013-07-11 Thread Sander Steffann
Hi,

 Anyone found out what happened with teredo.ipv6.microsoft.com ?
 
 http://translate.google.com/translate?hl=ensl=deu=http://www.heise.de/netze/meldung/IPv6-Tunnel-Microsofts-Teredo-Server-nicht-erreichbar-1915972.htmlprev=/search%3Fq%3Dteredo%2Bmicrosoft%2Bipv6%26safe%3Doff%26sa%3DX%26biw%3D1303%26bih%3D803%26tbs%3Dqdr:w
 
 Since yesterday we have quite an increase of NXDOMAIN in relevant dns 
 requests.
 
 Has Microsoft made the big step?

Almost :-)   This is what is happening now:

 As an attempt to measure the impact of this sunsetting, we would like to
 switch off the service for a few days. Resultant feedback and telemetry will
 help us inform the future of the Teredo service and its default configuration
 on Windows. We intend to conduct this experiment from  approximately July 9
 0:0:00 UTC, to July 15 0:0:00 UTC.

So it will come back, but it *is* the start of the sunsetting process.

Cheers,
Sander