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Date: Mon, 17 Dec 2007 08:47:27 +0900
From: Yukiyo Akisada <akisada@tahi.org>
Subject: [users:00449] Re: Release 1.5.0b1 Phase-2 PMTU - Test #9 Host Test
To: "Leino, Tammy" <tammy_leino@mentor.com>
Cc: <users@tahi.org>
Message-Id: <20071217084727.1e10b40c.akisada@tahi.org>
In-Reply-To: <2F83EB16CD718C43889CBCD31ECFD7F81B8801@na2-mail.mgc.mentorg.com>
References: <20071214104229.fbb84a47.akisada@tahi.org>	<2F83EB16CD718C43889CBCD31ECFD7F81B8801@na2-mail.mgc.mentorg.com>
X-Mail-Count: 00449

Hi, Tammy.

I heard that it is related to the translator.

To know more detail,
I think that asking IETF is the better way.

Regards,


On Fri, 14 Dec 2007 07:10:04 -0700
"Leino, Tammy" <tammy_leino@mentor.com> wrote:

> Thank you Yukiyo.
> 
> I have read this section many times trying to make it fit into test #9,
> but I still cannot make sense of it.  It doesn't make sense that the
> extra 8 bytes is a fragment header, because I cannot see why the packet
> needs to be fragmented.  Can you please explain why the packet needs to
> be fragmented.
> 
> Best Regards,
> Tammy Leino
> 
> 
> -----Original Message-----
> From: Yukiyo Akisada [mailto:akisada@tahi.org]
> Sent: Thursday, December 13, 2007 8:42 PM
> To: Leino, Tammy
> Cc: users@tahi.org
> Subject: Re: [users:00436] Re: Release 1.5.0b1 Phase-2 PMTU - Test #9
> Host Test
> 
> 
> Hi, Tammy.
> 
> Please check RFC 1981, Chapter 4.
> 
>     241       Note: A node may receive a Packet Too Big message
> reporting a
>     242       next-hop MTU that is less than the IPv6 minimum link MTU.
> In that
>     243       case, the node is not required to reduce the size of
> subsequent
>     244       packets sent on the path to less than the IPv6 minimun
> link MTU,
>     245       but rather must include a Fragment header in those packets
> [IPv6-
>     246       SPEC].
> 
> In this case, extra 8 bytes mean Fragment header.
> 
> And actual test specification is
> <http://www.ipv6ready.org/announcement/public_review20071204_p2core.html
> >.
> 
> Perldoc isn't the master.
> We are trying to follow the update of master specification,
> but sometimes perldoc contains old information.
> 
> Please use the specification located at ipv6ready.org.
> 
> Regards,
> 
> 
> On Wed, 12 Dec 2007 07:18:23 -0700
> "Leino, Tammy" <tammy_leino@mentor.com> wrote:
> 
> > Hello All,
> >  
> > I reported this issue last Thursday and have not yet heard back from
> anyone.  Do you require further clarification on any points?  If so,
> please let me know.
> >  
> > Best Regards,
> > Tammy Leino
> >  
> > 
> > -----Original Message-----
> > From: Leino, Tammy 
> > Sent: Thursday, December 06, 2007 4:42 PM
> > To: users@tahi.org
> > Subject: [users:00426] Release 1.5.0b1 Phase-2 PMTU - Test #9 Host
> Test
> > 
> > 
> > 
> > Hello All, 
> > 
> > There is a discrepancy in the test procedure diagram and description
> for this test.  The MTU in the Packet Too Big message is actually 56 for
> this test, and not zero as shown in the procedure diagram.
> > 
> >    TN2                    TR1                    NUT
> >     |                      |                      |
> >     |-------------------------------------------->|
> >     |   1.Echo Request     |                      |
> >     |   (1280 octets)      |                      |
> >     |                      |                      |
> >     |<--------------------------------------------|
> >     |   2.Echo Reply       |                      |
> >     |   (1280 octets)      |                      |
> >     |                      |                      |
> >     |                      +--------------------->|
> >     |                      |  3.Packet Too Big    |
> >     |                      |    (MTU 0)           |
> >     |                      |                      |
> >     |-------------------------------------------->|
> >     |   4.Echo Request     |                      |
> >     |   (1280 octets)      |                      |
> >     |                      |                      |
> >     |<--------------------------------------------|
> >     | 5.Echo Reply         |                      |
> >     |   (1288 octets)      |                      |
> >     |                      |                      |
> >     v                      v                      v 
> > 
> > Also, can someone please explain to me why the NUT would echo 1288
> bytes when it receives only 1280 bytes?  I am referring to #4 and #5 of
> the above diagram.
> > 
> > I am having trouble understanding why this test expects the NUT to
> fragment the echo reply when the packet size is equal to the IPv6
> minimum link MTU.  We do not fragment until we reach the link MTU of
> 1500.  Even if we set the link MTU to 1280, the IPv6 minimum link MTU,
> we should not fragment a 1280 byte echo reply packet.  I'm sure I am
> overlooking something here.  Your advice is greatly appreciated.
> > 
> > Best Regards,
> > Tammy Leino 
> > 
> > 
> 
> 
> ------------------------------------------------------------------------
> Yukiyo Akisada <akisada@tahi.org>
> 
> 


------------------------------------------------------------------------
Yukiyo Akisada <akisada@tahi.org>