> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:openib-general- > [EMAIL PROTECTED] On Behalf Of Hal Rosenstock > Sent: Saturday, March 05, 2005 6:18 PM > To: David M. Brean > Cc: [email protected] > Subject: Re: [openib-general] IB Address Translation service > > On Sat, 2005-03-05 at 10:22, David M. Brean wrote: > > There is an I-D for DHCP on IB. IPoIB defines a "broadcast" address and > > DHCP (and ARP) on IB use it. Could make RARP work using this mechanism, > > but as someone else pointed out, the IB hardware address contains a > > QPN. The I-D for IPoIB says something like: > > > > The link-layer address for IPoIB includes the QPN which might not be > > constant across reboots or even across network interface resets. > > Cached QPN entries, such as in static ARP entries or in RARP servers > > will only work if the implementation(s) using these options ensure > > that the QPN associated with an interface is invariant across > > reboots/network resets. > > That may be the requirement but I think there are some issues with > keeping the QPN invariant. Quoting Dror Goldenberg > (http://openib.org/pipermail/openib-general/2004-November/006765.html): > "Assigning specific QPN for ipoib requires allocation of QPN space which > is beyond IB spec verbs. Current verbs do not allow it. I don't have any > objection for that, except that you have to hold a set of preallocated > QPs with specific numbers and hand them over to privileged consumer when > requested to. I wouldn't commit that it will work on any HCA > architecture." > > -- Hal >
Just to add to Hal and Dave, it is not only that the QPN may not be constant, you can actually have few valid QPNs, one or more per partition, since each partition reflects the notion of an IP VLAN/Network the RARP should return different IP per partition, and the RARP caller should use different QPN in each case. I believe all the emails in this thread clarify why RARP is not a valid approach Yaron _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
