[openib-general] Latest IPoIB Bringup Questions

[Roland Dreier]

    Hal> After ifconfig'ing an IPv4 address and netmask< I see the
    Hal> that the QPN is filled in in the HWaddr (00-00-04-04). No
    Hal> other bytes change. Is that correct ? Wouldn't the lower
    Hal> bytes get filled in with some local GID ?

Actually with ifconfig I don't think you can see enough of the HW addr
to see the GUID part of the GID.  On my box I have:

    # ifconfig ib0
    ib0       Link encap:UNSPEC  HWaddr 00-00-04-04-FE-80-00-00-00-00-00-00-00-00-00-00

but

    # ip addr show dev ib0
    6: ib0: <BROADCAST,MULTICAST,UP> mtu 2044 qdisc pfifo_fast qlen 128
        link/[32] 00:00:04:04:fe:80:00:00:00:00:00:00:00:02:c9:01:07:8c:e4:61 brd 00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff

    Hal> Some questions/comments on this sequence: 1. In general, how
    Hal> long is the end node waiting before retransmitting a SA MC
    Hal> request ?

It should wait 1 second and back off from there.  But I think I have a
bug somewhere either in the IPoIB driver or the SA layer.

    Hal> 2. How are TIDs chosen ? It looks to me like there are 2
    Hal> different MC requests potentially outstanding with the same
    Hal> TID.

The SA layer uses idr.h to allocate the low TID -- so it shouldn't
reuse a TID until the previous request times out or is completed.

    Hal> The last request is the insufficient component mask issue.

Right, that should be possible to fix now with the new SA API.

    Hal> One other minor comment: Should we teach ifconfig to display
    Hal> Link Encap: INFINIBAND ?

Probably better to work on ip, since ifconfig has other issues (such
as using an ioctl limited to 14 bytes to get the HW addr)

 - R.