[ofa-general] Setting mtu on an IB port

[Pradeep Satyanarayana]

Sean Hefty wrote:
>>> I was hoping to set the IB mtu to 4096 instead of 2048 as shown in the
>>> ibv_devinfo.  Any ideas on that?
>>>
>> Mike, The issue here is likely that one of the nodes/ports may be in datagram
>> mode and the other one in connected mode.
> 
> I believe he's trying to control the IB MTU, not the IP MTU.
> 
> The IB MTU can be restricted based on the HCA capabilities or the switch
> capabilities that the HCA may be connected to.  Do you know if these support a
> larger MTU size?

Sean, You are right about the IB MTU. My guess was that he was trying to set both
(based on the 2044 in his mail).

I use the embedded SM rather than openSM. Hence guidance on that will be helpful.

Pradeep