#4121 IPv6 link local address allocation sometimes fails on fed-cloud2
Closed: Fixed None Opened 8 years ago by tomprince.

= bug description =
It appears that sometimes (on some underlying hosts?) link-local
IPv6 addresses can't be assigned because the fail duplicate-address-detection.

= bug analysis =
Some research suggests that this is due to hairpin mode being enabled on the underlying bridge interface on the host. (http://dachary.org/?p=1571)

= fix recommendation =
According to the above link, disabling hairpin_mode on the interface should fix this.
Something like:
echo 0 > /sys/class/net/br2003/brif/vnet1/hairpin_mode

Looks like fun thing to investigate. Lets have a look.

This should be fixed in the new cloud.

Please re-open if you are still seeing it.

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