Re: NM bug 684242 and other stuff

[Dan Williams <dcbw redhat com>]

On Wed, 2012-09-26 at 17:21 -0400, Pavel Simerda wrote:
> 
> ----- Original Message -----
> > From: "Dan Williams" <dcbw redhat com>
> > To: "Gene Czarcinski" <gene czarc net>
> > Cc: networkmanager-list gnome org
> > Sent: Wednesday, September 26, 2012 11:07:04 PM
> > Subject: Re: NM bug 684242 and other stuff
> > 
> > On Wed, 2012-09-26 at 14:56 -0400, Gene Czarcinski wrote:
> > > On 09/26/2012 02:38 PM, Dan Williams wrote:
> > > > There's some example keyfiles here:
> > > >
> > > > http://cgit.freedesktop.org/NetworkManager/NetworkManager/tree/src/settings/plugins/keyfile/tests/keyfiles
> > > >
> > > > manual IPv6 is for example:
> > > >
> > > > http://cgit.freedesktop.org/NetworkManager/NetworkManager/tree/src/settings/plugins/keyfile/tests/keyfiles/Test_Wired_Connection_IP6
> > > >
> > > > but that doesn't describe SLAAC.  For that, you just need:
> > > >
> > > > [ipv6]
> > > > method=auto
> > > What I am looking for (without diving into the Networkmanager code
> > > any
> > > more than I have too) is a keyfile configuration which will cause
> > > RA to
> > > be used for the default route
> 
> With method=auto, RA is always used for the default route.
> 
> > > and dhcpv6 for the client's IPv6 address
> 
> With method=auto, DHCPv6 address configuration is used after recieving
> RA with AdvManagedFlag.
> 
> Like here (sorry for re-posting the same link):
> 
> https://fedoraproject.org/wiki/Tools/NetworkManager/IPv6#DHCPv6_address_and_DNS_configuration
> 
> > > and,m if dhclient is used with my mods, a ddns update.
> 
> DDNS updates alredy work for you with your patch and with DHCP enabled by AdvManagedFlag in
> Router Advertisement, don't they?
> 
> > I believe (and either Pavel or Tore correct me if I'm wrong) that
> > would
> > should be:
> > 
> > 1) Using Router Advertisements and possibly setting the prefix too
> > 2) Setting the "Managed" flag for RA (AdvManagedFlag for radvd)
> > 3) Setting NM to "method=auto"
> 
> Exactly.
>  
> > This should cause the kernel to recognize your router and add a route
> > for it, but should not cause the kernel to use the prefix in the RA.
> > The Managed flag will cause NM to perform DHCPv6 for address
> > assignment
> > and DNS options.  In IPv6 with SLAAC (including DHCP) the default
> > router
> > is *always* determined from Router Advertisements;
> 
> Exactly.
> 
> > that's the confusing
> > bit for people used to IPv4.  In IPv6, the default router
> > determination
> > can be *completely* separate from address assignment.
> > 
> > Note that if you use DHCPv6 for address assignment, you'll only ever
> > be able to use /64, because that's all DHCPv6 supports.  The IPv6
> > standards
> > really, really, really want you to use RA as much as possible.
> 
> The fixed prefix length also applies to stateless config with RA. It's
> defined by IPv6 Addressing Architecture and anyone who deviates from
> it risks his equipment will react badly.
> 
> > > On the surface, I must say that I like keyfile a lot better than
> > > the ifcfg-rh stuff.
> 
> Me too.
> 
> > Yeah, though at least on Fedora we're going to live with ifcfg files
> > for
> > a long long time.  Since that's what admins know, and that's what
> > users
> > know, and that's how the documentation (including Google search
> > results)
> > are written for.  It's hard to change collective knowledge.
> 
> I'm actually going to write some manpages for keyfiles. Would this be of
> any help with the issue?

I think that would be great.

Dan