[ofw] Name resolution in WinVerbs/Multiple cards in one machine

[Hefty, Sean]

> thanks for your explanations. I already thought of some kind of DNS-related
> problem and will try to fix that tomorrow. In the meantime, I have another
> question: Is it sufficient if the name server returns the IPoIB address at any
> position in the host entry? It would be a problem for me if it had to be the
> first. And can the machines be in different sub domains and nets? I do still
> not understand how the IP/GID mapping of a remote port is done in WV - I would
> expect the need for some kind of out of band mechanism here, too.

The IP addresses of different machines sharing the same IB subnet should belong to the same IP subnet as well.  Otherwise you need an IP router in between and IP->IB address resolution becomes an issue.  Typically, the IP->GID mapping of a remote system is done using ARP or neighbor discovery (which is why you want systems on the same IP subnet).  The GID is part of the ARP response to a query.

- Sean