Re: ULE linux kernel code

[Gorry Fairhurst <gorry@erg.abdn.ac.uk>]

Thanks Bernhard, 

The Spec probably was not intended to be implemented this way, so I'd
suggest we need to look at this seriously. First, can I check one subtle
question below.


On 9/2/06 14:24, "Bernhard Collini-Nocker" <bnocker@cosy.sbg.ac.at> wrote:

> Dear all,
> 
> a while ago we have noticed that the ULE code in the recent Linux 2.6
> kernels (from 2.6.10 onwards, when ULE with optional headers was added)
> implements a "non-obvious" handling of IP-multicast and IP-broadcast
> packets in the one case when D bit (SNDU Destination Address Absent
> flag) is not set (equals 0), or in other words when a SNDU Destination
> Address (NPA/MAC) address is present. Instead of applying the filter
> only on unicast addresses the filtering is applied on ALL packets.
Are broadcast packets (MAC ff:ff:ff:ff:ff:ff) also caught by this filter?
- or are they currently always forwarded?

> Consequently multicast/broadcast packets (whose SNDU DestAddr does not
> match the one set interface hardware address) are discarded in the
> driver. This kind of stringent filtering, however, may confuse
> operators/users.

<snip>.