[openib-general] [RFC] IB address translation using ARP

[Sean Hefty]

Hal Rosenstock wrote:
>>I'm struggling with understanding how translation can even occur in this case. 
>>What DGID is used when querying for the path record, and how is it obtained?
> 
> Isn't it the DGID of the next hop IP router ? (I suppose in the case of
> multiple IPoIB subnets on the same IB subnet, it could shortcut somehow
> like NHRP does in terms of ATM v. CLIP (Classic IP over ATM).

How is the DGID of the next hop IP router used when connecting?  As an aside, do 
the IPoIB subnets all fall into the same broadcast domain?

>>What does SDP do in this case?
> 
> Same as AT. It does the route lookup and ARPs for and then asks for the
> PathRecord of the next hop IP router.

I guess I'm confused here.  This gives a path record between the host system and 
the IP router.  How is that used to establish a connection to the actual 
destination?  What values (DLID, DGID, pkey, etc.) go in the CM REQ message, and 
how are those values obtained?

- Sean