[ofa-general] MTU in IPoIB

[Or Gerlitz]

Wiegers, Bert wrote:
> In our default-setup we are using IPoIB. This is set up with a MTU of 65520
> ib0       Link encap:UNSPEC  HWaddr 80-00-00-48-FE-80-00-00-00-00-00-00-00-00-00-00
>           UP BROADCAST RUNNING MULTICAST  MTU:65520  Metric:1
[...]
> ib0: enabling connected mode will cause multicast packet drops
> ib0: mtu > 2044 will cause multicast packet drops.
> So should I limit the MTU to 2044?

Please take a look on Documentation/infiniband/ipoib.txt, specifically commit b49ca "IPoIB: Document newish features" should help you understand things better.

Or.