Hi Jeff/Paolo: Thanks for helping clarify this issue. I'll leave it to the UML development community to decide how and when to modify things to provide the necessary filtering. In the meantime, I'll simply continue to configure my multicast-based interfaces as promiscuous so that my protocol software knows that it has to handle packets that weren't destined for the interface.
Regards, Al Stephens Wind River > -----Original Message----- > From: Paolo Giarrusso [mailto:[EMAIL PROTECTED] > Sent: Friday, August 04, 2006 7:10 AM > To: Jeff Dike; Stephens, Allan > Cc: Paolo Giarrusso; > user-mode-linux-devel@lists.sourceforge.net; > user-mode-linux-user@lists.sourceforge.net > Subject: Re: [uml-devel] [uml-user] Promiscuous mode interface bug? > > Jeff Dike <[EMAIL PROTECTED]> ha scritto: > > > On Thu, Aug 03, 2006 at 01:08:51PM -0700, Stephens, Allan wrote: > > > Where I think my confusion is arising is in the details of how > > the > > > filtering > > > controlled by the promiscuous setting is actually done. If a > > packet > > > with > > > the "wrong" destination address arrives at an interface, who > > checks to > > > see > > > whether the interface has been configured as promiscuous and > > > passes/discards it accordingly? I have naively assumed that this > > > was handled in > > hardware > > > on the > > > NIC card in a real system, but is it really done by software? > > > Ah, a light goes on. I believe that it is done on the card. > > Yes, it is, you can set one (or even more, for special > purposes) MAC addresses to accept on a card or configure it > as "no hardware filtering done"; I've observed a network > driver doing this, and I think set_mac is the hook for this. > > > > What I seem to > > > be > > > observing in my UML testing is that *nobody* is doing this > > filtering, > > > resulting in > > > unwanted packets being handed to my protocol (which sits directly > > on top > > > of the > > > Ethernet driver). > > > > And since UML doesn't have "cards", it may be that the > driver should > > do the filtering at the bottom layer and it isn't. > > I agree too; we may check however if the network stack > implements support for such "dumb" cards (probably by setting > a flag) to avoid coding it ourselves. > > Chiacchiera con i tuoi amici in tempo reale! > http://it.yahoo.com/mail_it/foot/*http://it.messenger.yahoo.com > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ User-mode-linux-user mailing list User-mode-linux-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
