VLAN tagged packets received by application are corrupted

VLAN tagged packets received by application are corrupted

[Amit Agarwal]

Hi all,

I have query on vlan tagged packets received by network interface.

Problem: I have application which would receive all packets on the interface
and process them ( this could be including vlan tagged packets). However when
the 8021q (vlan) module is not loaded and the appropriate interfaces for all
the IDs are not created I see that the application is not able to decode them.
When we capture with tcpdump/tshark/wireshark as well we see that the packets
are not correctly displayed. The Ethernet header type itself is not correctly
identified and thus the rest of the packet cannot be decoded. What could be
causing this and is there a way to fix this?

-- 
 Thanks,
-aka

VLAN tagged packets received by application are corrupted

[Anupam Kapoor]

most likely you offload enabled on your card, try disabling that to see if
tcpdump does the right thing for you

----
kind regards
anupam

On Fri, Nov 21, 2014 at 10:19 AM, Amit Agarwal <amit@amit-agarwal.co.in>
wrote:

> Hi all,
>
> I have query on vlan tagged packets received by network interface.
>
> Problem: I have application which would receive all packets on the
> interface
> and process them ( this could be including vlan tagged packets). However
> when
> the 8021q (vlan) module is not loaded and the appropriate interfaces for
> all
> the IDs are not created I see that the application is not able to decode
> them.
> When we capture with tcpdump/tshark/wireshark as well we see that the
> packets
> are not correctly displayed. The Ethernet header type itself is not
> correctly
> identified and thus the rest of the packet cannot be decoded. What could be
> causing this and is there a way to fix this?
>
> --
>  Thanks,
> -aka
>
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>



-- 
In the beginning was the lambda, and the lambda was with Emacs, and Emacs
was the lambda.
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VLAN tagged packets received by application are corrupted

[Amit Agarwal]

On 14-11-21 12:51:29, Anupam Kapoor wrote:
> most likely you offload enabled on your card, try disabling that to see if
> tcpdump does the right thing for you
ethtool -k <intf> - does not show anything for vlan.

More information: 

Kernel is 2.6.32
Driver being used in tg3.


-- 
 Thanks,
-aka

VLAN tagged packets received by application are corrupted

[Greg KH]

On Fri, Nov 21, 2014 at 06:20:01PM +0530, Amit Agarwal wrote:
> On 14-11-21 12:51:29, Anupam Kapoor wrote:
> > most likely you offload enabled on your card, try disabling that to see if
> > tcpdump does the right thing for you
> ethtool -k <intf> - does not show anything for vlan.
> 
> More information: 
> 
> Kernel is 2.6.32

You do realize that that kernel version is over 313 _thousand_ changes
behind the current kernel release?  Things have changed a lot since
then, sorry.  If you are stuck with such an old and obsolete kernel
version, please get support from the vendor that is forcing you to run
such an insecure thing.

best of luck,

greg k-h