Bonding and duplicate TCP ACK-s with RedHat ES5

[Jens Brey]

Hi Jeff,

youre right with youre answer if you use a active-active bonding with 
loadbalancing.
In active-passive mode is this not necessary.
The problem sounds for me like a bug in the bonding.

@Istvan: Can you post youre configuration and which parameters do append 
on the bonding module?

Regards,
Jens


Tétényi István schrieb:
> Jeff Larsen wrote:
> Dear Jeff,
>
> Thank you for your response.
>
> I will check the switch on Monday. The switch itself is the standard 
> Dell 1855 switch, Dell PowerConnect switch.
>
> Is anyone has other idea than the switch conf to resolve this problem?
> As far as I am aware the switch config has not been changed for a long 
> time, and it was well before the ES5 upgrade.
> Obviously I do not neglect this possible problem source.
>
> Kind regards,
>  Istvan
>
>> On Sat, Apr 5, 2008 at 2:43 AM, Tétényi István <tetenyi at sztaki.hu> wrote:
>>   
>>> Hi,
>>>
>>>  We have recently upgraded from  RedHat ES4 to ES5 on a Dell Blade 1855.
>>>
>>>  In our configuration we use bonding mode = 1 on the gigabit ethernet
>>>  interfaces internally, between the individual blades and the internal
>>>  blade switches.
>>>  Our intention is to have an active backup configuration.
>>>
>>>  However, there were some errors.
>>>
>>>  The most characteristic was that the number of connections that are in
>>>  close_wait state has  increased significantly.
>>>
>>>  After some sniffing, it turned out that there are dual TCP ACK-s
>>>  arriving from the bonded ethernet interface.
>>>
>>>  I wonder, if anyone has met this problem or has some advice how to remedy it
>>>
>>>     
>>
>> It's probably your switch. Some switches require special configuration
>> to handle bonded NICs. You need to create a 'trunk' or 'group' of the
>> ports connected to your bonded NICs. Just be careful not to forget and
>> move the patch cables around on the switch.
>>
>>   
>
>
> -- 
>
> Pista
>
> =====================================================================
>  Istvan Tetenyi                              e-mail:tetenyi at sztaki.hu
>  Computer and Automation Institute               phone: +361-279-6022
>  Budapest, Victor Hugo u 18-22                   fax:   +361-279-6021
>  H-1132. Hungary
> =====================================================================
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