(Applogies for not maintaining thread id, I'm not subscribed.) >> We don't have any clean interfaces by which to do this MAC >> programming, and we do need something for it soon.
>Yep, that's been on my long term wish list for a while, as well. >Overall I would like to see a more flexible way of allowing the net >stack to learn each NIC's RX filter capabilities, and exploiting them. >Plenty of NICs, even 100Mbps ones, support RX filter management that >allows scanning for $hw_limit unicast addresses, before having to put >the hardware into promisc mode. > A thought I had when I discovered this ability in the Natsemi/NS83815 chip was to use these RX filters for perfect multicast DA matching until they ran out, and then reverting to the normal Multicast DA matching mechanisms. Another alternative use I thought of was to use these filters to filter out different ethernet protocol types e.g. if an interface is only going to be processing IPv4 packets, program these filters to only accept frames with type 0800 for IP and 0806 for ARP, reverting to non-filtering if there are too many protocol types, as per the way the interfaces operate today. I think it could be useful to expose the ability to have the NIC ignore broadcast packets, or more generally, expose the three catagories of address recognition that NICs seem to allow to be enabled / disabled - unicast, multicast and broadcast. If an interface then didn't need to have broadcast reception enabled e.g. an IPv6 only interface (or Appletalk), then it wouldn't be, preventing the host from having to process broadcasts it's going to ignore anyway. A future common scenario where this ability might be useful would be LANs with a mix of IPv4 only, IPv4/IPv6 and IPv6-only nodes. The ability to enable/disable unicast, multicast and broadcast address recognition individually on a NIC seems to be widespread - I've found that the original early to mid 90s Ne2K chip, the NS8390D, the Netgear FA311/FA312 chip, the NS83815 and the SMC Epic/100 chip all have specific individual register values for those three types of addresses. Regards, Mark. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
