[Babel-users] Babel MAC auth fails due to packet reordering

[Toke Høiland-Jørgensen]

Daniel Gröber <dxld at darkboxed.org> writes:

> Hi,
>
> On Wed, May 04, 2022 at 02:16:08PM +0200, Juliusz Chroboczek wrote:
>> We still need to understand why you're getting systematic packet
>> reordering. 
>
> See the two attached pcaps, babel-reorder-sender is on the AP wlanX device
> and babel-reorder-receiver is on the other side of the wireless link.
>
> I'm also including babel packets in both directions as Toke asked
> (wireshark filter: babel || icmpv6).
>
> You can see the reordering at sender packet no 12 vs. receiver packet no
> 161.
>
> Toke, I'm running without the DSCP iptables rule but I'm seeing CS0 anyway
> so it's probably not that, right?

No, doesn't look like it. The power save hypothesis also better explains
the long delays involved.

Could you please try turning off power saving on the client device and
see if that makes the problem go away? 'iw dev wlan0 set power_save off'
should do the trick. You'll also need to make sure no other devices are
connected to the AP while you're testing (or that they also all have
power save disabled). Not sure if there's any way to check on the AP
side if it's actually delaying the multicast frames, so isolating the
client is probably the safest bet :)

-Toke