Any changes in kernels the last month (Iptables related)

[Joseph Salisbury]

On 09/05/2014 09:58 AM, Doug Smythies wrote:
> On 2014.09.05 01:10 Kim Emax wrote:
>
>> I was wondering if there´s been any changed in the later kernels? 
>>
>> I´m using a ubuntu server with tow nics as a router, firewall, DHCP etc.
>> The last month out of nowhere and without any changes (other > than regular
>> updates from apt) my LAN has been fucked on upload (0.07mbit), while the WAN
>> has +40Mbit. I´ve rebooted switches and WLAN > router, changed the LAN nic and
>> has a laptop directly to the router, no luck.
>> By changing in the iptables rules i´ve managed to tweak the LAN upload to 1-2mbit,
>> still works really bad on LAN though. Taking a test > at hastighedstest.tdc.dk shows
>> NO speed at first, then after a while it goes up a bit up to 3mbit, then falls back
>> and stays around > 1mbit. Wierd behaviour.
>> Current Kernel: 3.2.0-67-generic, Ubuntu 12.04
> Yes, the same thing happened to my Ubuntu 12.04 server which is my main router to
> my LAN with the same kernel.
>
> The lost time and frustration trying to figure it out was staggering.
> I also suffered significant collateral damage.
>
> In my case the root issue was MTU and some new enforcement thereof, giving a lot
> ICMP packets saying something like:
> "ICMP port unreachable, packet too long and don't fragment bit is set"
>
> O.K. so the real root issue is that some clients (windows clients and only a
> couple of NIC cards (it seems)) ignore the MTU and send larger packets.
>
> Anyway, and in my case, the issue is resolved in the next kernel, or by going back to the previous kernel.
>
> Linux doug-64 3.2.0-68-generic #102-Ubuntu SMP Tue Aug 12 22:02:15 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
>  
> ... Doug
>
>
>

Hi Doug,

When you say it was resolved by going to the next kernel, do you mean
you apply the latest updates and the next kernel is what came in with
that(3.2.0-68)?  Or do you mean the next kernel that is in the next
Ubuntu release like Trusty or Utopic. Does the bug exists in 3.2.0-67
but not 3.2.0-68?

Kim, it would be really helpful if you can open a Lauchpad bug report
against the kernel.  That will let us review your logs, version info,
etc.  You can do this by running the following from a terminal window:
'ubuntu-bug linux'.  If the bug is in fact fixed in 3.2.0-68, the
easiest fix would be to just apply the latest updates.

Thanks,

Joe