* How to disable TCP checksum calculation?
@ 2011-05-07 4:37 Wu, Xia
2011-05-07 7:28 ` Alexander Clouter
0 siblings, 1 reply; 3+ messages in thread
From: Wu, Xia @ 2011-05-07 4:37 UTC (permalink / raw)
To: alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org,
linux-wireless@vger.kernel.org
Hi, ALL,
I'm studying TCP transporting efficiency. Now I want to disable TCP checksum calculation, but I cannot find the right way to disable it. Who can give me a help on how to disable TCP checksum on Linux?
Thanks
xia
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: How to disable TCP checksum calculation?
2011-05-07 4:37 How to disable TCP checksum calculation? Wu, Xia
@ 2011-05-07 7:28 ` Alexander Clouter
2011-05-07 13:38 ` Eric Dumazet
0 siblings, 1 reply; 3+ messages in thread
From: Alexander Clouter @ 2011-05-07 7:28 UTC (permalink / raw)
To: linux-kernel; +Cc: linux-wireless
Wu, Xia <xia.wu@intel.com> wrote:
>
> I'm studying TCP transporting efficiency. Now I want to disable TCP
> checksum calculation, but I cannot find the right way to disable it.
> Who can give me a help on how to disable TCP checksum on Linux?
>
Look at using TCP checksum offloading to see the effects:
http://en.wikipedia.org/wiki/TCP_Offload_Engine
----
berk:/home/alex# ethtool -k eth0
Offload parameters for eth0:
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: on
tx-vlan-offload: on
ntuple-filters: off
receive-hashing: on
----
Cheers
--
Alexander Clouter
.sigmonster says: Dental health is next to mental health.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: How to disable TCP checksum calculation?
2011-05-07 7:28 ` Alexander Clouter
@ 2011-05-07 13:38 ` Eric Dumazet
0 siblings, 0 replies; 3+ messages in thread
From: Eric Dumazet @ 2011-05-07 13:38 UTC (permalink / raw)
To: Alexander Clouter, Wu, Xia; +Cc: linux-kernel, linux-wireless
Le samedi 07 mai 2011 à 08:28 +0100, Alexander Clouter a écrit :
> Wu, Xia <xia.wu@intel.com> wrote:
> >
> > I'm studying TCP transporting efficiency. Now I want to disable TCP
> > checksum calculation, but I cannot find the right way to disable it.
> > Who can give me a help on how to disable TCP checksum on Linux?
> >
> Look at using TCP checksum offloading to see the effects:
>
> http://en.wikipedia.org/wiki/TCP_Offload_Engine
>
> ----
> berk:/home/alex# ethtool -k eth0
> Offload parameters for eth0:
...
Not sure what We meant here. TCP standard requires checksums to be set,
you cannot 'disable it'. Only possible thing in linux stack is to
offload tcp checksum computation to network card, if hardware permits
it.
By the way, the loopback interface (lo) pretends to support this
feature, so we dont compute tcp checksums for loopback.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2011-05-07 4:37 How to disable TCP checksum calculation? Wu, Xia
2011-05-07 7:28 ` Alexander Clouter
2011-05-07 13:38 ` Eric Dumazet
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