[openib-general] IB mcast question

[Sean Hefty]

>One of the reserved bytes in the MGID is 1 rather than 0 and it's using
>an IPv4 signature (0x401b) ?

It uses a signature of 0x4001 to avoid conflicts with ipoib groups.

>Where does the qkey come from on the creation of the group ?

The qkey is the same as the IPv4 address.

I need to spend some time looking at the QKeys of the QPs and the multicast
group to understand how one of the receivers worked.

- Sean