RE: please read: Clarification on GUID's universal/loc al bit

Resending...

> -----Original Message-----
> From: Diego Crupnicoff 
> Sent: Sunday, May 23, 2004 10:12 PM
> To: 'H.K. Jerry Chu'; [email protected]
> Cc: [email protected]; [email protected]; 
> [email protected]; [email protected]
> Subject: RE: [Ipoverib] please read: Clarification on GUID's 
> universal/local bit
> 
> 
> The IB spec is somewhat problematic on this issue. The spec 
> does state that global scope is obtained by setting the "u" 
> bit, but at the same time defines the IB GUID as an "IEEE 
> EUI-64 identifier" and refers to its spec for details (where 
> global scope is defined to be achieved by clearing the "u" bit).
> 
> We know of deployed IB implementations where the "u" bit in 
> the GUID is cleared.
> 
> The IBTA LWG has discussed this matter but no formal 
> resolution has yet been voted. The LWG is looking for a way 
> to solve the problem without affecting any existing implementation.
> 
> Given the above, I would suggest that IPoIB should define the 
> way to derive an IPv6 interface identifier from an 
> IB-port-GUID without making any assumptions on the value of 
> its "u" bit.
> 
> Thanks,
> 
> Diego
> 
> 
> 
> > -----Original Message-----
> > From: H.K. Jerry Chu [mailto:[email protected]]
> > Sent: Sunday, May 23, 2004 4:22 PM
> > To: [email protected]
> > Cc: [email protected]; [email protected]; 
> > [email protected]; [email protected]
> > Subject: [Ipoverib] please read: Clarification on GUID's 
> > universal/local bit
> > 
> > 
> > A question was raised during the IESG review of the
> > encapsulation and multicast draft
> > 
> > http://www.ietf.org/internet-drafts/draft-ietf-ipoib-ip-over-i
> > nfiniband-06.txt
> > 
> > regarding the use of GUID as an interface identifier.
> > 
> > IPv6 spec (RFC2373 and RFC3513) requires, when an interface
> > identifier is derived from an IEEE EUI-64 identifier, that 
> > the universal/local bit to be inverted. The following is 
> > quoted from RFC3513:
> > 
> > "Modified EUI-64 format interface identifiers are formed by
> > inverting the "u" bit (universal/local bit in IEEE EUI-64 
> > terminology) when
> > forming the interface identifier from IEEE EUI-64 
> > identifiers.	In
> > the resulting Modified EUI-64 format the "u" bit is set to 
> > one (1) to indicate global scope, and it is set to zero (0) 
> > to indicate local scope."
> > 
> > IBA spec Vol1 Release 1.1 Nov 6, 2002, section 4.1 states
> > 
> > EUI-64: IEEE defined 64-bit identifier...
> > 
> > 
> > *	The universal/local bit in IEEE EUI-64 shall be set to one to
> > 	indicate global scope or set to zero to indicate local scope.
> > 	The manufacturer assigns an EUI-64 with global scope set. A SM
> > 	may assign additional EUI-64 with local scope indicated.
> > 
> > According to Dan Cassiday, the IBTA LWG chair, the above
> > paragraph clearly implies that a GUID has the universal/local 
> > bit inverted already from an EUI-64 identifier, and thus can 
> > be readily used as an IPv6 interface identifier.
> > 
> > I'd like to hear, especially from those IB hardware
> > manufacturers, if the above is consistent with your 
> > implementation. That is, the GUIDs you provide will have 
> > universal/local bit set to 1.
> > 
> > Separately if you think the IBA spec should be made more
> > clear above the relation between GUID and EUI-64, you should 
> > submit your suggestion to IBTA.
> > 
> > Thank you,
> > 
> > Jerry
> > 
> > IPoIB WG co-chair
> > 
> > [email protected]
> > Sr. Staff Engineer
> > Solaris Networking & Security Technology
> > Sun Microsystems, Inc.
> > (650) 786-5146
> > 
> > 
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> > 
>