[ofa-general] [Bug 450] New: IPoIB BW drop (measured with iperf) with mtu=1500 on x86 RH4UP3

Moni Levy monil at voltaire.com
Wed Mar 14 02:24:28 PDT 2007


On 3/13/07, Michael S. Tsirkin <mst at dev.mellanox.co.il> wrote:
> > >Why are you playing with ifc mtu?
> >
> > We needed to do some IP forwarding tests between IB and Ethernet and
> > wanted to have the same MTU for the eth0 and ib0 interfaces, after
> > that we reproduced that in a peer to peer configuration.
>
> OK but PMTU discovery would do this better, won't it?

I'm not sure (it will probably drop some packets at the beginning).
Anyway lower MTU should work.

> As a side note, with 1.5K MTU it's probably better to use datagram mode
> anyway.

Now I see that I missed that in the report. We used datagram mode.

-- Moni

>
> --
> MST
>



More information about the general mailing list