<html>
<body>
<font size=3>At 10:39 PM 6/29/2005, Bill Strahm wrote:<br><br>
<blockquote type=cite class=cite cite="">
<blockquote type=cite class=cite cite="">
------------------------------<br><br>
Message: 2<br>
Date: Wed, 29 Jun 2005 09:00:37 -0700<br>
From: Roland Dreier <rolandd@cisco.com><br>
Subject: Re: [openib-general] IP addressing on InfiniBand networks<br>
To: Caitlin Bestler <caitlin.bestler@gmail.com><br>
Cc: "Lentini, James" <James.Lentini@netapp.com>,
Christoph Hellwig<br>
<x-tab> </x-tab>
<hch@lst.de>,<x-tab> </x-tab>openib-general
<openib-general@openib.org><br>
Message-ID: <5264vxi256.fsf@topspin.com><br>
Content-Type: text/plain; charset=us-ascii<br><br>
Caitlin> An assigned GID meets all of the requirements
for an IA<br>
Caitlin> Address. I think taking advantage of that
existing<br>
Caitlin> capability is just one of many options that can
be done<br>
Caitlin> by the IB CM rather than forcing IB specific
changes up<br>
Caitlin> to the application layer.<br><br>
Just to be clear, the IBA spec is very clear that a GID _is_ an IPv6
address.<br><br>
- R.<br><br>
</blockquote>Just to be REALLY clear - IANA has not allocated IPv6
address space to any Infiniband entities - so they are not Internet IPv6
addresses. GIDs are formatted like IPv6 addresses but in no sense
should EVER be used at an IP layer 3 address.<br><br>
From an IPoIB stance - IB is just a very over engineered Layer 2 that
has a singularly large MAC address.<br><br>
From an IB ULP point of view - how you get to the layer 2 address that
is needed to perform communications that do not include IP, it isn't a
problem - but let me tell you.... The leadership of the IETF is scared of
IB because of saying things IB GIDs _ARE_ IPv6
addresses.</blockquote><br>
Being the person who led the addressing definition for IB, I can state
quite clearly that GID are NOT IPv6 addresses. They were
intentionally defined to have a similar look-n-feel since they were
derived in large part from Future I/O which had them as real IPv6
addresses. But again, they are NOT IPv6 addresses. <br><br>
For IP over IB, it is unfortunate that we could not have simply used a
raw datagram service as that would have made life very simple but we are
in the state we are so that means there is a UD transport providing a
layer 2 Ethernet equivalent of functionality. <br><br>
Mike</font></body>
</html>