jumbograms (& em) & nfs a no go

[Terry Lambert]

Michal Mertl wrote:
> I then left one computer at 4.9 and upgraded the other to 5.0. When I
> mount a partition from 5.0 machine I found out, that copying reliably
> works only from 5.0 to 4.9. The other way around I see messages 'em0:
> discard oversize frame (ether type 800 flags 3 len 67582 > max 6014)' on
> 5.0 and the copying stalls. On 4.9 machine I later see 'nfs server
> 10.0.0.2:/usr: not responding'. The interface is stuck for some time - can
> be revived by changing mtu back to 1500 and down/up sequence.

Implies the sending host is not honoring the MTU restriction when
deciding whether or not to frag packets.

-- Terry