[ILUG] Slow IPv6 when using bridge networking on CentOS 6.x

[FRLinux]

I ran into this one a while back where CentOS 5.x used to be slow on VM
running through the network bridge. The fix at the time was to issue an :
ethtool -K eth0 tso off. So i did just that and here are my current
settings.

# ethtool -k eth0
Offload parameters for eth0:
rx-checksumming: on
tx-checksumming: off
scatter-gather: off
tcp-segmentation-offload: off
udp-fragmentation-offload: off
generic-segmentation-offload: off
generic-receive-offload: on
large-receive-offload: off

Now this unfortunately does not work anymore. I have searched a few forums
and no one seems to have run into that one.

Here are the speeds compared on v4 and v6 (this is from HEAnet's mirror)

wget -O /dev/null -c
http://ftp.heanet.ie/pub/centos/5.8/isos/x86_64/CentOS-5.8-x86_64-bin-2of8.iso
Resolving ftp.heanet.ie... 2001:770:18:aa40::c101:c140, 193.1.193.64
Connecting to ftp.heanet.ie|2001:770:18:aa40::c101:c140|:80... connected.
15,804,132  1.23M/s  eta 44m 35s

wget -4 -O /dev/null -c
http://ftp.heanet.ie/pub/centos/5.8/isos/x86_64/CentOS-5.8-x86_64-bin-2of8.iso
47,537,840  7.70M/s  eta 14m 51s

Tested this several times over, this is giving me the same results. If I
disable the bridging mode on the network card, i get full speed over IPv6.

Anyone?

Cheers,
Steph
-- 
Step by Step, the penguins are taking my sanity away.