[ipxe-devel] ipxe hangs on boot when receiving a jumbo frame

[ahmed]

Hi everyone,

We have spent some days trying to debug this problem with no success.
we hope to find some help here.
As indicated on the mail subject, we have three servers A, B, and C on
the same broadcast domain.
A and B communicate via a multi-cast protocol with frame of size 9000
(real packet size less than 256 but they are padded with 0 to MTU size).

When booting C receive those packets  as a result it timeout on boot, we
have on debug message with unknown protocol 0000.
We suppose that only part of the payload is read and then either an
overflow screw up everything or the remaining part of the payload is
considered as a new packet and mess up things.
We have also tried decreasing MTU from 9000 (in A,B) to 4000 and 2000
but still the same error.
C boots only when we bring back A,B MTU to 1500


We have tried to increase some buffers values but we still can't solve
this problem. We still get the unknown protocol 0000 message and can't
boot the system.

Thank you in advance to any one who may be able to give us some hints.

---
Ahmed Amamou