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

[Juliusz Chroboczek]

>
> While this is not fatal for the reordering fix per-se your RTT patch also
> breaks because of this AFAICT. Since the IHU tstamps only ever arrive via
> unicast. At least with my `unicast true` babeld config.

More exactly, with "unicast true" babeld will send a IHUs over unicast,
which will in turn force it to include an unscheduled unicast hello.  You
should be able to work around the issue by setting

    rfc6126-compatible true

in babeld.  However, this has other consequences, such as breaking
source-specific routing.

> Nothing bad seems to happen if I just comment this out :) Do you have have
> any pointers as to what needs to be impl-emented in bird to properly support
> unicast hellos?

You don't need full support for unicast hellos, you just need to parse the
sub-TLVs of unicast hellos in order to extract the timestamp.

-- Juliusz