[ofa-general] Re: [PATCH 1/4] ib/ipoib: specify TClassand FlowLabelwith PR queries for QoS support

[Michael S. Tsirkin]

> AFAIK, when using the 64K MTU setting for IPoIB, if the remote side
> doesn't support RC then things go wonky.

The scenario you describe works fine for me.
What does go wonky for you?

> For TCP things *might* be saved
> by path mtu discovery -

MTU discovery is not restricted to TCP AFAIK.

> but PMTU is driven by ICMP errors which are
> not generated by an IB network.

IPoIB CM code generates them in software.

> I suspect that if you use IPoIB a
> mixed configuration like that you are going to want to have routing
> table entries that override the MTU for non-RC capable destinations.
> But I haven't tried this..

Did you actually try interoperability between IPoIB with
and without RC support? You might be pleasantly surprised.

-- 
MST