On Thu, 19 Jul 2007 16:23:48 +0200 Krzysztof Halasa <[EMAIL PROTECTED]> wrote:
> Stephen Hemminger <[EMAIL PROTECTED]> writes: > > > 1) non-accelerated device > > * all frames show in promiscious mode > > * tag is part of the frame that shows up > > in tcpdump, and then gets stripped by the 8021q module. > > Sure. It's IMHO good and working, modulo the tag being removed > on the master device (optional cloning or something, IIRC). > > > 2) rx tag stripping device > > * all frames show in promiscious mode > > * tag is in skb but NOT passed to tcpdump > > 3) rx vlan acceleration > > * only frames that for vlan's that are registered show up > > in promisicous mode > > * tag is in skb but NOT passed to tcpdump > > I wasn't aware of devices doing 3. Aren't we able to tell them > to receive all packets anyway (even unknown VLANs#)? See NETIF_F_HW_VLAN_FILTER (e1000, etc). > > Unfortunately, the tag is lost as part of the VLAN acceleration process > > so it is not a simple matter of changing code in AF_PACKET receive > > to restore the tag. > > I'm not sure if we really want it. If needed we can disable > acceleration, can't we? While accelerated we can see the packets > (without tags) on logical devices. Not at runtime, acceleration is always on if you compile kernel with vlan support. That is a design mistake as far as I can tell. > However seeing unknown tags on master device (with tcpdump etc) > would certainly be useful. Only in promiscuous mode. In some sense tag is part of the mac address. - 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
