[Oisf-users] Percentage of dropped packets

[Dave Remien]

The ixgbe large-receive-offload setting should only be turned on when the
NIC is the endpoint (i.e., in a server say); extra work needs to be done to
get the content of the packets when you're using the NIC (and machine) in
bridge/inline mode.  I usually compile the ixgbe driver to turn this
setting off by default for inline use.

Cheers,

Dave

On Wed, May 30, 2012 at 9:49 AM, Chris Wakelin <c.d.wakelin at reading.ac.uk>wrote:

> On 30/05/12 10:39, Peter Bates wrote:
> >
> > Hello again all
> >
> > Adding a point to my own reply...
> >
> > On 30/05/2012 09:29, Peter Bates wrote:
> >> When I first had the 10Gb NIC up I was seeing (in ifconfig) rx
> >> dropped increasing and no rx packets received - and subsequently
> >> nothing to capture in tcpdump/etc - however as the advice above
> >> changes all the settings to 'off' I was unsure which one
> >> actually solved my problem.
> >
> > My ixgbe settings are now: Offload parameters for eth6:
> > rx-checksumming: on tx-checksumming: on scatter-gather: on
> > tcp-segmentation-offload: on udp-fragmentation-offload: off
> > generic-segmentation-offload: on generic-receive-offload: on
> > large-receive-offload: off rx-vlan-offload: off tx-vlan-offload:
> > off ntuple-filters: off receive-hashing: off
> >
> > ... I find when I turn 'large-receive-offload' on then my NIC
> > stops receiving packets and drops everything.
> >
> > I'm receiving traffic from a Cisco SPAN not sure whether it
> > encapsulates the packets or makes them larger than 1514 hence this
> > setting disturbing the capture.
>
> It might be worth trying a higher MTU, say "ifconfig eth6 mtu 1522".
> Are there VLAN tags on the port? Our Extreme border switches add VLAN
> tags to the port mirror in one direction only :-o
>
> It might also be worth compiling your own ixgbe driver from
> http://sourceforge.net/projects/e1000/files/ixgbe%20stable/ or with
> PF_RING as the one shipped in the 2.6.x kernels seems very old.
>
> I'm using PF_RING-enabled ixgbe-3.7.17 (DNA version at the moment) and
> have left the offload parameters at the defaults:
>
> Offload parameters for dna0:
> rx-checksumming: on
> tx-checksumming: on
> scatter-gather: on
> tcp-segmentation-offload: on
> udp-fragmentation-offload: off
> generic-segmentation-offload: on
> generic-receive-offload: on
> large-receive-offload: on
> rx-vlan-offload: off
> tx-vlan-offload: off
> ntuple-filters: off
> receive-hashing: off
>
>
> driver: ixgbe
> version: 3.7.17-DNA
> firmware-version: 0x18f60001
> bus-info: 0000:0c:00.0
> supports-statistics: yes
> supports-test: yes
> supports-eeprom-access: yes
> supports-register-dump: yes
> supports-priv-flags: no
>
> Best Wishes,
> Chris
>
> --
> --+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+-
> Christopher Wakelin,                           c.d.wakelin at reading.ac.uk
> IT Services Centre, The University of Reading,  Tel: +44 (0)118 378 2908
> Whiteknights, Reading, RG6 6AF, UK              Fax: +44 (0)118 975 3094
> _______________________________________________
> Oisf-users mailing list
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>



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