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

[Juliusz Chroboczek]

> To test dont-fragment I first set it to disabled and changed the
> (wireguard) interface MTU from 1420 to 1280 at runtime. Doing this I can
> observe babel hellos being fragmented in tcpdump.
> 
> When setting dont-fragment true this trick doesn't work and the neighbour
> relationship to the other node doesn't get established.
> 
> So it looks like it's working.

Thanks for the report.

I think I'll rework it to use the per-message option as you suggested in
a previous mail, so that probe-mtu automatically triggers dont-fragment on
the affected interface.  One configuration option less.

Then, after you confirm it still works for you, I'll merge into master.

Thanks again,

-- Juliusz