Re: [Bugme-new] [Bug 37172] New: Enabling 802.1q vlan causes some packets to be received with a vlan id of 64

(switched to email.  Please respond via emailed reply-to-all, not via the
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On Fri, 10 Jun 2011 19:20:58 GMT
bugzilla-daemon@bugzilla.kernel.org wrote:

https://bugzilla.kernel.org/show_bug.cgi?id=37172

           Summary: Enabling 802.1q vlan causes some packets to be
                    received with a vlan id of 64
           Product: Networking
           Version: 2.5
    Kernel Version: 2.6.39
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: Other
        AssignedTo: acme@ghostprotocols.net
        ReportedBy: a.reversat@gmail.com
        Regression: Yes

From which kernel version did we regress?  Was 2.6.38 OK?

Thanks.

Created an attachment (id=61502)
 --> (https://bugzilla.kernel.org/attachment.cgi?id=61502)
Packet capture of problem

I added a vlan to my main network card by doing :

vconfig add eth0 6

Then I got huge packet loss when pinging e.g google (around 70% packet loss).

After checking a packet capture it seems that some packets come in with a vlan
tag even though they shouldn't. In my capture I see them with a vlan id of 64
where they shouldn't even be 802.1q tagged.

Kernel version is 2.6.39 and I am using the forcedeth driver so I don't know if
it is related to the network stack or the forcedeth driver.

Attached is the relevant capture. Note how packet with seq 2 for instance is
tagged and packet with seq 5 isn't.

I'll test this with the latest 3.0 rc and update the bug report if the problem
is fixed in there.

On Mon, Jun 13, 2011 at 7:43 PM, Andrew Morton
[off-list ref] wrote:

From which kernel version did we regress?  Was 2.6.38 OK?

I can confirm this bug is present in 2.6.38.6

I'll try and see if I can reproduce it on a 2.6.37

I've tested 2.6.37.6 and 3.0.0-rc2 and the bug is still reproducible
in both kernels. I'll try a 2.6.36 to see if it was present in it too.

Has this been tested on other hardware ? I'm still unsure if it's a
driver issue or if it's something else.

On Tue, Jun 14, 2011 at 9:31 AM, Antoine Reversat [off-list ref] wrote:

On Mon, Jun 13, 2011 at 7:43 PM, Andrew Morton
[off-list ref] wrote:

quoted

From which kernel version did we regress?  Was 2.6.38 OK?

I can confirm this bug is present in 2.6.38.6

I'll try and see if I can reproduce it on a 2.6.37

On Wed, Jun 15, 2011 at 12:13 PM, Antoine Reversat [off-list ref] wrote:

I've tested 2.6.37.6 and 3.0.0-rc2 and the bug is still reproducible
in both kernels. I'll try a 2.6.36 to see if it was present in it too.

Has this been tested on other hardware ? I'm still unsure if it's a
driver issue or if it's something else.

Infact it's probably a driver bug : I've tried on a coworkers computer
with a different network adapter and it works flawlessly. I'll contact
the forcedeth people about this.