Bonding and duplicate TCP ACK-s with RedHat ES5

[Jeff Larsen]

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.

-- 
Jeff