# values in sysctl.conf not loaded on boot.

**URL:** <https://forums.suse.com/t/values-in-sysctl-conf-not-loaded-on-boot/23442>\
**Category:** SLES Virtualization\
**Created:** [December 21, 2012, 6:51pm UTC](https://forums.suse.com/t/values-in-sysctl-conf-not-loaded-on-boot/23442 "2012-12-21T18:51:50Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![frlarson](https://avatars.discourse-cdn.com/v4/letter/f/73ab20/32.png) [@frlarson](https://forums.suse.com/u/frlarson)\
**Post date:** [December 21, 2012, 6:51pm UTC](https://forums.suse.com/t/values-in-sysctl-conf-not-loaded-on-boot/23442/1 "2012-12-21T18:51:50Z")

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I have two installations of SLES11 SP2 on X86-64 that I use to host KVM VMs. They are configured for bridging networking and it all works after I use sysctl to set  
net.bridge.bridge-nf-call-ip6tables = 0  
net.bridge.bridge-nf-call-iptables = 0  
net.bridge.bridge-nf-call-arptables = 0

I have added these three lines to the end of /etc/sysctl.conf, expecting that the system will set them on boot. This does not happen. /etc/sysctl.conf is being loaded at boot as I can see other values from that file change when I change them. Because of this I can not load VMs at boot with any reliability. If I change these settings and then load the VMs everything works fine. Why is SLES not setting these values?

Thanks in advance.

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**Author:** ![ab1](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@ab1](https://forums.suse.com/u/ab1)\
**Post date:** [December 21, 2012, 8:05pm UTC](https://forums.suse.com/t/values-in-sysctl-conf-not-loaded-on-boot/23442/2 "2012-12-21T20:05:45Z")

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I hit this type of thing earlier this week with other values and I believe  
the explanation is here in the Notes section:

[http://linux.die.net/man/8/sysctl](http://linux.die.net/man/8/sysctl)

Basically some module loaded after the sysctl stuff is initially applied  
(pretty early on apparently) is re-setting those values. How do you get  
past this? Put the commands you want, the actual sysctl commands, in  
/etc/init.d/after.local so that they are called after all of the other  
stuff loads:

Good luck.

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**Author:** ![frlarson](https://avatars.discourse-cdn.com/v4/letter/f/73ab20/32.png) [@frlarson](https://forums.suse.com/u/frlarson)\
**Post date:** [December 21, 2012, 8:24pm UTC](https://forums.suse.com/t/values-in-sysctl-conf-not-loaded-on-boot/23442/3 "2012-12-21T20:24:49Z")

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I found the answer and thought I would report it here as others are probably seeing similar problems. The /proc entries needed to implement the sysctl settings I need are created when the bridge module is installed. That module is installed when br0 is created, much later than boot.sysctl is run so those commands fail. I am seeing that there are many similar things associated with SLES boot system. They will show up as a “/proc/sys/net/ipv6/conf/all/autoconf: No such file or directory” message where the exact file depends on which module is needed. When I added bridge to INITRD\_MODULES= in /etc/sysconfig/kernel and rebuilt the initrd with mkinitrd, the modules was loaded earlier and things worked.