On 01.12.10 at 13:18, Jiri Bohac <jbohac@suse.cz> wrote: On Wed, Dec 01, 2010 at 08:08:54AM +0000, Jan Beulich wrote: I'm actually opposed to changing this back without knowing that it's actually used in the EC2 environment.
I guess you can set it to =n and see if someone complains then. If it turns out it is used, please make it =y. See below why.
I don't think we should bluntly disable anything.
The argument of sysconfig not being able to cope with IPV6=m is certainly bogus - if so, the tool needs to be fixed.
... the sysctl configuration interface of IPv6 (and IPv4 as well, FWIW) is really really frustrating wrt the effect and availability of the tunables during boot. A simple example of the horror:
Say you want to set accept_ra to 0 to disable autoconfiguration on an interface. To do this, you need to : - have IPv6 available (i.e. loaded if it is a module) - the interface must not yet be up, otherwise it is too late to stop it from autoconfiguring
If you want to enable the interface with something like ifplugd/NM/udev when it appears, doing everything in the right order is quite complicated. If the scripts needed to check/load the ipv6 module, this would be a nightmare. Even worse, you may need to configure the network interface in initrd, etc...
All of this should be a non-issue as long as ipv6.ko gets loaded early enough on systems that actually need it. I can't see what's that difficult here.
Disabling IPv6 (through YaST/sysconfig) is another problem. The old method of blacklisting the module does no longer work, because e.g. the bonding module depends on the ipv6 module. Disabling IPv6 with the sysctl cannot be done unless the module is already loaded, at which point, interfaces may have started autoconfiguring. The only option left would be a kernel command-line option.
Having ipv6 built-in everywhere minimises the frustration of people putting their own ipv6 setting to /etc/sysctl.conf.
When put there through YaST, it should simultaneously store appropriate module load options or hooks into a modprobe configuration file. When put there manually, people should know what they're doing (i.e. whether they need to put it there, in modprobe's config files, or both). Jan -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org