Date: Sat, 24 Aug 2013 03:11:26 +0200 From: Luigi Rizzo <rizzo@iet.unipi.it> To: Harika Tandra <htandra@gloriad.org> Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org> Subject: Re: Netmap ixgbe stripping Vlan tags Message-ID: <CA%2BhQ2%2BhVOhoQQFG5MOYa%2B0kSEet7qk1FRmqqiWU%2B7t22CtKa7A@mail.gmail.com> In-Reply-To: <FC9BCAD9-5D16-4E70-A9C5-FA9D9A22B84C@gloriad.org> References: <FC9BCAD9-5D16-4E70-A9C5-FA9D9A22B84C@gloriad.org>
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responding to the first email in the thread: netmap by design does not modify the setting of the card (vlan, hwcsum, tso/lro, promisc, ...). The main practical reasons behind this choice are that i) in many cases both settings make sense when in netmap mode, ii) we can use existing OS tools/ioctl to modify the settings without having to replicate them within the netmap code. vlan tag insertion/removal is probably the one feature which should be always disabled in netmap mode. For others, the case is not so clear. As an example, having tso and hwcsum enabled is useful to postpone those expensive ops to the very last moment; the upcoming version of netmap supports scatter-gather I/O, and when used to interconnect virtual machines through the VALE switch you don't even need to do the segmentation or checksumming. cheers luigi On Fri, Aug 23, 2013 at 12:36 AM, Harika Tandra <htandra@gloriad.org> wrote: > Hi all, > > I am running Netmap with "intel 10G 82598EB" card in promiscuous mode. > While capturing packets via Netmap the driver is stripping off Vlan tags. > I tested my setup, I am able to see Vlan tags when the same card is in > promiscuous > mode without Netmap. > > This maybe due to the netmap related changes to the device driver code. > But I don't know much about drivers. I would appreciate any help or pointer > regarding this. > > Thanks, > Htandra. > > > > > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" > -- -----------------------------------------+------------------------------- Prof. Luigi RIZZO, rizzo@iet.unipi.it . Dip. di Ing. dell'Informazione http://www.iet.unipi.it/~luigi/ . Universita` di Pisa TEL +39-050-2211611 . via Diotisalvi 2 Mobile +39-338-6809875 . 56122 PISA (Italy) -----------------------------------------+-------------------------------
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