Re: [Qemu-devel] eepro100 multicast

[Stefan Weil]

Am 25.09.2010 21:11, schrieb Dunc:
> Hi all,
>
> I've been trying to set up some olives running inside qemu to practice
> for Juniper exam. I came across the multicast issue when enabling VRRP
>
> After lots of googling and reading forums, where people have being doing
> hacky patches, I found a page that suggests this has been fixed now,
> just not in a formal release
>
> (here for reference)
> http://www.internetworkpro.org/wiki/Using_QEMU_with_Olive_to_emulate_Juniper_Routers#Getting_and_Installing_QEMU
>
> I had a look through gitweb and can see there has indeed been a commit
> to fix multicast in eepro100 and so I've built a qemu based on latest
> git (as of yesterday). Unfortunately it doesn't seem to fix things for
> me, however I do have a different error now....
>
> eepro100: feature is missing in this emulation: Multiple IA bit
>
>
> The setup of this link is quite simple, I have 2 qemus running using tap
> mode for network, and I have bridged them together on my host (Linux)
> When I configure the network I can successfully ping across the link
> with no problems, but as soon as I enable VRRP on either end, I start to
> get the above error at regular intervals (I assume it's each time VRRP
> sends a multicast hello), and also my link stops pinging altogether.
> When I remove VRRP config, the link pings again.
>
> Does anyone know what's going on, or if I'm doing anything wrong?
>
> Thanks in advance,
>
> Dunc


The OS which was used here is based on FreeBSD.

I reviewed the latest sources of Linux, FreeBSD and NetBSD.
They all reset the multiple IA bit (multi_ia in BSD) to zero,
but I did not find code which sets this bit to one
(like it is done by Juniper routers).

Running Windows guests also does not set this bit.

Intel's Open Source Software Developer Manual does not
give much information on the semantics related to this bit,
so I had to guess how it works.

My patch could help Dunc, but if anybody has more information
or driver code which makes use of this bit, that would be
really helpful.

Regards
Stefan