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

[Daniel Gröber]

Hi Juliusz,

On Sat, Jul 23, 2022 at 09:44:58PM +0200, Juliusz Chroboczek wrote:
> >
> > 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.

Ah I see. That could be an option I suppose, since I don't need SSR.

> > 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.

I'm literally testig a patch that does just that now, sounds like I'm on
the right track then. Thanks!

--Daniel