Settings in /etc/sysctl.conf not sticking at boot

[Jonathan Underwood]

Hi,

On a fully updated F7 box I have added this line to /etc/sysctl.conf:

net.netfilter.nf_conntrack_tcp_be_liberal = 1

However, on reboot, this seems to have no effect. Eg. On a freshly
rebooted system:

# cat /proc/sys/net/netfilter/nf_conntrack_tcp_be_liberal
0

And so that setting doesn't seem to have been applied. Without editing
that file, if I do:

# /sbin/sysctl -p
net.ipv4.ip_forward = 0
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.accept_source_route = 0
kernel.sysrq = 0
kernel.core_uses_pid = 1
net.ipv4.tcp_syncookies = 1
net.netfilter.nf_conntrack_tcp_be_liberal = 1

then, the setting sticks:

# cat /proc/sys/net/netfilter/nf_conntrack_tcp_be_liberal
1

Anyone able to shed some light on why this is so? (Reported as BZ #312481)

Jonathan.

[Jonathan Underwood]

On 29/09/2007, Jonathan Underwood  wrote:
> Hi,
>
> On a fully updated F7 box I have added this line to /etc/sysctl.conf:
>
> net.netfilter.nf_conntrack_tcp_be_liberal = 1
>
> However, on reboot, this seems to have no effect. Eg. On a freshly
> rebooted system:
>
> # cat /proc/sys/net/netfilter/nf_conntrack_tcp_be_liberal
> 0
>
> And so that setting doesn't seem to have been applied. Without editing
> that file, if I do:
>
> # /sbin/sysctl -p
> net.ipv4.ip_forward = 0
> net.ipv4.conf.default.rp_filter = 1
> net.ipv4.conf.default.accept_source_route = 0
> kernel.sysrq = 0
> kernel.core_uses_pid = 1
> net.ipv4.tcp_syncookies = 1
> net.netfilter.nf_conntrack_tcp_be_liberal = 1
>
> then, the setting sticks:
>
> # cat /proc/sys/net/netfilter/nf_conntrack_tcp_be_liberal
> 1

For the benefit of the archives, and anyone in the future searching
for this issue - the reason is that, during boot, sysctl is called by
the /etc/init.d/network service. Any values in /etc/sysctl.conf set
for kernel modules not loaded at that point will be ignored.