Re: failed to set IPv6 default route

[Gene Czarcinski <gene czarc net>]

On 09/24/2012 12:30 PM, Dan Williams wrote:
> On Mon, 2012-09-24 at 08:05 -0400, Gene Czarcinski wrote:
> > On 09/23/2012 08:56 AM, Gene Czarcinski wrote:
> > > I have been doing some work trying to improve IPv6 dhcp support in
> > > NetworkManager.  This has involved a lot of (virtual) testing. One
> > > thing I began to notice is a lot of the following message appearing in
> > > syslog:
> > >
> > > [nm-system.c:1121] nm_system_replace_default_ip6_route(): (p32p1):
> > > failed to set IPv6 default route: -7
> > >
> > > The only way I have been able to get an IPv6 default route set is to
> > > use manual configuration and specify a gateway.  Everything else seems
> > > to produce this message.
> > >
> > > OK, is this a bug or is there something about configuration I do not
> > > understand?
> > My question concerning if this is a bug stands.
> >
> > However, I have been playing around (marvelous what you can do with some
> > qemu/kvm/libvirt virtual guests when you do not care if things get
> > really screwed up).  I thried using NetworkManager (the applet) to set a
> > default route but nothing seemed to work except specifying the gateway
> > when manually configuring IPv6.
> >
> > I finally googled what appears to be (sort of) an answer. enter
> > something like the following command line command:
> >
> >       ip  -6  route  add  default  via <fill_IPv6_address_of_'router'>
> > dev  eth0
> So that's essentially what NM is trying to do, actually, but NM is
> trying to do it with netlink (which is what /sbin/ip uses too actually)
> but apparently the netlink options we're adding aren't quite correct
> here.  They unfortunately change periodically when kernel changes
> happen.  -7 appears to be NLE_INVAL, which would indicate the kernel
> doesn't think the route we gave it is valid.  We'd have to dig a bit
> further down to figure out what that error actually is.
>
> Last time I had to do this, I had to rebuild /sbin/ip and make it print
> out the exact netlink packet it was sending to the kernel.  Then I had
> NM print out its packet and compared the two.  If only there was an
> easier way...
I am currently running 0.9.4.0 and in the process of updating to 0.9.7.0 
is see if that makes a difference.

Gene