[openib-general] [PATCH] IPOIB: Use a GRH when appropriate for unicast packets

[Jason Gunthorpe]

On Wed, Feb 07, 2007 at 02:40:51PM -0800, Sean Hefty wrote:
> Are you referring to the SLID in the CM REQ?  If so, I've been looking at 
> this issue as well.  I simply cannot think of any way to come up with this 
> LID, and my current solution is to punt this problem over to the passive 
> side, which could use the SLID of the router that the CM REQ is received 
> from.  If not, well, then I just rambled more than usual.

Yes, this is the problem.

The active side clearly cannot learn what the SLID of the passive
side's router should be.

We don't want to have the routers snoop and alter CM GMPs.

The passive side cannot use information from the LRH to get the router
LID since the LRH may not be reversible.

The only option seems to be to have the passive side do a path record
query on a SGID in the CM REQ...

This is a spec problem unfortunately.

Jason