[Bridge] Re: tg3 bridge problems
gorgo at broadband.hu
Mon Jan 10 11:49:14 PST 2005
On Mon, Jan 10, 2005 at 02:41:34PM -0500, Neil Horman wrote:
> Gergely Madarasz wrote:
> >On Mon, Jan 10, 2005 at 12:40:57PM -0500, Neil Horman wrote:
> >>Gergely Madarasz wrote:
> >>>On Mon, Jan 10, 2005 at 11:04:55AM -0500, Neil Horman wrote:
> >>>>Strange. My concern was that the tg3 interface has its hardware reset
> >>>>whenever its set to be up, and part of that is a resetting of its
> >>>>receive mode. If for some reason IFF_PROMISC was cleared after you set
> >>>>it using brctl, the interface might be taken out of promisc mode. Do
> >>>>you have any iptables rules running that might drop bpdus?
> >>>No iptables rules az all. Btw iptables wouldn't prevent tcpdump from
> >>>seeing the packets, would it?
> >>>Could it be that the driver perhaps has a problem setting promisc mode
> >>>when resetting the hardware?
> >>Not really sure about this. One experiment is worth a thousand guesses
> >>I suppose....... I'll try and let you know. :)
> >I did some other checks, like adding an explicit ifconfig eth0 promisc,
> >then looking at tcpdump output - I didn't see any stray packets like I
> >usually do, just ethernet broadcasts and unicasts to my mac, this also
> >points to a problem that the ethernet interface is actually not in
> >promisc, while the driver thinks it is.
> >And it is probably not a driver-only issue. I've got older machines with
> >tg3 running fine with bridge (with an older tg3 driver), and eth1 on the
> >same machine also runs fine. On another machine I tested today, an IBM
> >x326, the same thing happens - eth0 broken, eth1 fine. Would access to one
> >of these machines help? :)
> I've got a tg3 card here. I'll try re-create it as soon as I have time.
Sounds great, but I expect it will not occur with a random tg3 card,
> Just out of curiosity, are you running tcpdump against the physical
> interface or the bridged interface? I do recall some issues involving
> using PF_PACKET on virtual interfaces, that might cause you to not see
> some packets that the physical interface really does receive.
The physical interface of course. I wouldn't have a chance seeing the
bpdu's on the bridge interface because they're handled by the bridge
driver and not passed on :)
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