[Babel-users] babels bug with uninitialized data somewhere?

[Juliusz Chroboczek]

>> There's nothing obviously wrong.  Here's an example of a source-specific
>> TLV (the one at time 06:20.362230 in the wifi capture):

> So this does imply some sort of memory corruption issue on parsing
> that "martian" packet?

I don't want to make any guesses.  Matthieu's code has been through some
churn lately, and we've fixed some minor bugs and typos.  Matthieu, what
about putting the latest version in the public git?  I'm sure Dave can
deal with our dirty rebasing habit.

>> (you're probably the only person in the world who thinks /27 is a round
>> number).
>
> 32 is a round number!

Indeed.  It's the sum of two primes.

> I would certainly like merely to export the /24 (and ipv6 /61) to the
> universe from each box but have never figured out how.

First, install a blackhole or unreachable route for the whole /24.  It's
a good thing to do in any case, since it will shoot any packets that are
destined for an interface that's currently down and might otherwise follow
the default route:

  ip route add unreachable 192.168.4.0/24 proto static

(I prefer unreachable, since it makes debugging marginally easier, but
Real Men (and Real Women) use blackhole routes.  I know, I'm a wimp.)

Then export this route as usual (babeld doesn't care that it's unreachable
-- as far as it's concerned, it's a perfectly good static route):

  redistribute ip 0.0.0.0/0 le 24 allow

No idea how to do it through UCI, you'll need to ask Gabriel.

> I turn it off (it has a noisy fan) and for sane values of "boom", the
> whole network switches over to going through the wan or adhoc ports.

You appear to be running with a very high hello interval, so the value of
boom is on the order of a minute, right?

> Compared to what would have happened if I'd tried vlans or some other
> bridging solution, this was marvelous.

Isn't your use case exactly what STP was designed for?  Set the STP root
to the edgerouter, and put an alternate root with slightly lower priority
on your other router.  (Unlike Babel, though, STP won't handle the meshy
part of your network, and it won't attempt to optimise your traffic --
everything will follow the STP tree, even when shortcuts are possible.
Unlike TRILL, however, it's a simple, well-designed, clean protocol that
works beautifully in the particular class of topologies it was designed for.)

-- Juliusz