[Babel-users] MTU based routing for tunnel based babel networks?

[Juliusz Chroboczek]

> I can observe (some) hellos using the padding depending on the option
> setting. Problem is when I force the interface MTU to 1280 instead of the
> initial 1420 the padded hellos get dropped and don't reach the other side
> as you'd expect, but the regular sized hellos still make it through and so
> the neighbourship relationship stays up.

Clarified in the other mail, good.

> Here's an idea: what if we pad the IHU response instead of all hellos? That
> might have slightly less control overhead when RTT isn't enabled as you
> don't need to respond to every hello then? I'm not sure how babeld
> schedules IHU sending exactly.

The Hellos are periodic, so the overhead is constant.  The number of IHUs
is proportional to the number of neighbours, so there might be arbitrarily
many of those.

I'm pretty sure it doesn't matter much in practice, but at least with
Hellos the amount of overhead is easy to predict.

-- Juliusz