Re: Disabling ip4 and IPV6 on F20

["Robert M. Albrecht" <lists romal de>]

Hi Dan,

I'm using the gnome settings application.

Switching off IPv4 is remembered and displayed graphically correct. But 
the ipv4 configuration is still there and still working.

Switching off IPv6 is remembered and displayed graphically correct. But 
IPV6 is still there, it only degrades from a global unicast adress to 
link local only. This is what you described in your post, but I think 
this is not what the average user (aka me) would expect.

Something has changed between Fedora 20 RC1 and Fedora 20 release. The 
graphical user interface elements seems to work.

Regards,
Robert

Am 17.12.2013 23:54, schrieb Dan Williams:
> On Sun, 2013-12-15 at 06:37 +0100, Robert M. Albrecht wrote:
> > Hi,
> >
> > my system has a built in ethernet interface wich is working perfectly
> > fine on IPV4 and IPV6.
> >
> > I added a second interface via usb for wiresharking some stuff (this way
> > I don't get my own traffic in the packet dumps).
> >
> > I don't want or need an IP-stack on this second interface.
> >
> > In network manager there is on top of the IPV4 and IPV6 config pages an
> > on/off button.
> When you say "in network manager", do you mean the GNOME system settings
> application, in the network panel?  There are on/off slider switches
> there for both IPv4 and IPv6, and if they value does not stick, then
> that is a bug in the GNOME control center.
>
> > For IPV4 this buttons seems to have no effect at all. It's off-position
> > is not even saved when applying or closing the dialog.
> >
> > For IPV6 something happens. All addresses except local link are deleted,
> > no DNS and routing.
> NetworkManager 0.9.8 and lower implement an "IPv6 ignored" option to
> remain compatible with the long time ago when NetworkManager did not
> support IPv6 at all.  This is likely what the "off" button is doing in
> the GUI you are using.  It doesn't actually mean IPv6 is disabled for
> the interface, it simply means that NetworkManager will not perform any
> IPv6 addressing itself.
>
> However, the *kernel* does do IPv6 link-local addressing, and will also
> do IPv6 SLAAC if you've let it.  So just because NetworkManager isn't
> doing any IPv6 configuration, that doesn't mean something else isn't.
>
> NetworkManager 0.9.9+ may implement actual IPv6 disabling, but we
> haven't heard of a great use-case for it, since having an IPv6
> Link-Local address on the interface (which the kernel will always
> provide) is almost never a problem, even with FCoE.
>
> > But if link local still remains where is the difference between
> > disabling IPV6 or enabling and choosing link local configuration only ?
> If IPv6 is "ignored" (ie, the "off" button), NetworkManager will not
> process any IPv6 Router Advertisements and will not set up a global IPv6
> address on your interface, and will not process any DNS servers or
> search domains from the Router Advertisement either.  It will also not
> perform DHCPv6 addressing, either alone or as requested by the IPv6
> router.
>
> Dan
>
> > Did I missunderstand the gui and the on/off buttons have some other
> > effect ? Or is it simply broken ?
> >
> > cu romal
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