[openib-general] Re: IPoIB still not working [was IPoIB FAQ Update]

[Hal Rosenstock]

On Mon, 2004-12-06 at 10:43, Doug Ledford wrote:
> On Mon, 2004-12-06 at 07:09 -0500, Hal Rosenstock wrote:
> > Hi Josh,
> > 
> > On Sun, 2004-12-05 at 23:02, Josh England wrote:
> > 
> > Your IPoIB configuration looks fine.
> 
> Well, he had identical hardware addresses on n0 and n1 for his ib0 and
> ib1 interfaces respectively.  This would likely keep the linux network
> stack from actually sending the packet back to the originating host and
> instead convince it that it's intended for internal consumption I would
> think.  Try putting a different HW MAC address on your different ib?
> ports and see if that gets the packets flowing.

The HW address is truncated in ifconfig as it is 20 bytes which is
longer than the 16 I think ifconfig (and arp) support.

You can tell the full IB HW addresses from ip neigh. If these were the
same (due to duplicate GUIDs being programmed), this would cause a
problem as you indicate.

(I will add this tidbit into the next IPoIB FAQ).

-- Hal