Re: [Qemu-devel] net packet storms with multiple NICs

[Michael Tokarev <mjt@tls.msk.ru>]

Paul Brook wrote:
>> I immediately reproduced the problem locally.  It turns out that
>> kvm reflects packets coming from one guest NIC on another guest
>> NIC, and since both are connected to the same bridge we're getting
>> endless packet storm.  To a level when kvm process becomes 100%
>> busy and does not respond to anything but `kill -9'.
> 
> You created a network loop. It is working exactly as expected.
> Create the same topology with a physical network hub and a pair of NICs and 
> you'll get the same end result.

Paul, I know what the result is.  But mind you, I talked about something
different, namely: why, using "obvious" way, you get a packet storm/loop
instead of a working network.  And if that loop is useful in the first
place.

I've got answers to both already :)

Thanks

/mjt