[Babel-users] Babel - bug ?

[Juliusz Chroboczek]

> I am using default configuration of babel, just -l and -C are added
> on both sides. I really dont know if is this a bug, or I am doing
> something wrong. But is strange because, everything is working
> good. But in third maybe fourth iteration I came to that problem. As
> I can see in debug output, metric is 65535. If I restart babel
> everything is OK than.

The link cost estimation hasn't converged yet.  By default, Babel uses
a very large hello interval on wired links (see the -H option in the
manual page), you may want to reduce it if you want faster convergence.

As a rough guide, link state convergence will happen after 3 hello
intervals.  (Once link state has converged, route convergence will
happen faster -- 100 ms per hop is typical.)

> Do you have any suggestions for using your protocol over limited
> bandwidth connection, or any other suggestion for my case ?

Babel should work fine at 38 kbps, even if you reduce the hello interval.

One thing you may want to experiment with is the -l flag, which will
cause Babel to react immediately to notifications from the link layer
(LCP in your case).  Since I don't really understand cross-layer
notifications, it's marked as experimental in the manual page; let me
know how it works for you.

> The only thing I am really missing its security, do you have any
> plan to implement security in babel. Or is there any easy way I can
> do it my self(begginer in C), if you dont plan. Lets say symmetrical
> key would be enough, as it is in olsr protocol.

What is your attack model?  I.e. what are you trying to protect against?

If your link is insecure, an attacker may use simpler techniques to
poison your network than participating in the routing protocol.  It
doesn't make much sense to secure Babel if you haven't secured ARP.

                                        Juliusz