Re: slowly or no configured connection usage

[Ingo Flaschberger <ingo flaschberger gmail com>]

Am 04.08.2015 um 23:52 schrieb Dan Williams:
> On Mon, 2015-08-03 at 03:00 +0200, Ingo Flaschberger wrote:
> > Hi,
> >
> > I use nm 0.9.10 with debian jessie at a raspberry pi.
> >
> > Problem 1:
> > If I configure a single connection with auth ipv4, auto ipv6, auto
> > connect and delete all other connections it takes severall minutes after
> > reboot till the connection is used.
> > Also a new "eth0" connection is always generated.
> > Connection name is "internet", config is attached.
> I think this one is probably due to the kernel-assigned IPv6LL address
> that the device gets when something in the boot process brings the
> interface IFF_UP.
>
> > Problem 2:
> > If I configure a single connection with static ipv4, link-local ipv6,
> > auto connect and delete all other connections after reboot the
> > connections is never used.
> > Only a new generated "eth0" connection is used.
> > Connection name is "emergency", config is attached.
> This is due to the same reason.
>
> > Digging into code - I wonder why a new connection is generated and why
> > nm_utils_match_connection / check_possible_match / check_ip6_method  and
> > check_ip4_method behave such strange?
> When NM starts up, it will read the existing interface configuration and
> attempt to match it to a stored connection.  If it doesn't match, NM
> tries very hard not to touch the interface, because something else
> configured it and NM won't blow that away.
>
> In case #2, I'll bet that the generated connection "eth0" was
> ipv4.method=disabled, ipv6.method=link-local.  The connection you
> created was ipv4.method=manual.  On bootup, the interface has only an
> IPv6 link-local address, but not the static address from your
> connection.  Therefore, the runtime config of the interface (ipv6ll
> only) doesn't match any stored connection, and the existing
> configuration wins.
yes, thats the case (dumped the settings yesterday), but interface also 
has a real ipv6 address assigned.
> We realize that treating an interface with only an IPv6LL address isn't
> very useful though, especially since the kernel will assign an LL
> address whenever the interface is brought IFF_UP, which often happens
> during boot for various reasons.  Therefore, NM 1.0.4 and later have
> switched to ignoring interface configurations that have only an IPv6LL
> address, and will use another configured connection instead.  We could
> potentially backport that to 0.9.10, or at least make the patch
> available to distros.

can you show me the affected code-lines?  then I could wrapup the patch 
very quick.

currently I use a cron-job to keep the interfaces up.

Kind regards,
   Ingo Flaschberger