Actually, I was a part of that thread - see my comments beginning with http://www.open-mpi.org/community/lists/devel/2006/03/0797.php.
Perhaps I communicated poorly here. The issue in the prior thread was that few systems nowadays don't offer at least some level of IPv6 compatibility, even if nothing more than mapping IPv6 addresses to IPv4. My point in that thread was that some types of systems (e.g., embedded systems) don't - they have no ability to interact with IPv6 at all - but that these are not commonly found in the high performance world (the focus of OpenMPI). Although I expect hetero operations to be fairly common, I don't expect to see too many high performance systems that have no library support at all for IPv6. Hope that clarifies my comment. The intent is to fully support both types of systems anyway, so I'll concede that the point (i.e., how unusual the situation might be) is somewhat moot. On 9/6/06 8:13 AM, "Bogdan Costescu" <bogdan.coste...@iwr.uni-heidelberg.de> wrote: > On Fri, 1 Sep 2006, Ralph Castain wrote: > >> The only use case I am really concerned about is that of a Head Node >> Process (HNP) that needs to talk to both IPv6 and IPv4 systems. I >> admit this will be unusual, > > This and other aspects were discussed or at least mentioned in a > thread starting at: > > http://www.open-mpi.org/community/lists/devel/2006/03/0781.php > > I don't know why you think that this (talking to different nodes via > different channels) is unusual - I think that it's quite probable, > especially in a heterogenous environment. > > However, if the present discussion is only about a proof of concept > version, then I'd say that anything to show IPv6 functionality would > be acceptable.