default route handling of udhcpc

[Steffen Sledz <sledz@dresearch-fe.de>]

Recently we hit a problem with the default route handling of udhcpc.

The provided script busybox/files/simple.script (aka /etc/udhcpc.d/50default) removes all existing default routes before setting new routes. I think that's wrong.

If multiple interfaces offer default routes (via DHCP, static config, or any other way) there is no reason to prefer one over another (without having any additional information). So the script should only add the new default route. A short search in the internet brings up a lot of useful scenarios for multiple default routes.

So i tried to remove the part from the script which removes the existing routes. This led to a confusing situation.

If the script uses "route add default gw ..." (which is the case if /sbin/ip is not installed) everything seems to work fine.

But if /sbin/ip (from the busybox package) is installed the "ip route add default via ..." results in an "ip: RTNETLINK answers: File exists" error. In my opinion this is an error in the busybox ip implementation.

Opinions?

Regards,
Steffen

-- 
DResearch Fahrzeugelektronik GmbH
Otto-Schmirgal-Str. 3, 10319 Berlin, Germany
Tel: +49 30 515932-237 mailto:sledz@dresearch-fe.de
Fax: +49 30 515932-299
Geschäftsführer: Dr. Michael Weber, Werner Mögle;
Amtsgericht Berlin Charlottenburg; HRB 130120 B;
Ust.-IDNr. DE273952058