[CentOS] /etc/sysctl.conf edit not permanent

[John R Pierce]

Joseph L. Casale wrote:
>> What exactly did you add to /etc/sysctl.conf?
>>
>> Do you have any errors when you run "sysctl -p" on the command line as root?
>>
>> Filipe
>>     
>
> Hi,
> I added the following to /etc/sysctl.conf:
> net.ipv4.ip_forward = 1
> sysctl -p does not show any errors.
>
> So after a #service network restart, I see this:
> Shutting down interface eth0:  [  OK  ]
> Shutting down loopback interface:  [  OK  ]
> Disabling IPv4 packet forwarding:  net.ipv4.ip_forward = 0
> [  OK  ]
> Bringing up loopback interface:  [  OK  ]
> Bringing up interface eth0:  [  OK  ]
> Bringing up interface eth1:
> Determining IP information for eth1... done.
>
> But a sysctl -p shows the right info after? Is this behavior normal?
>   

sysctl -p  reads the /etc/sysctl.conf file and sets whatever options are 
in there, so if you run that, its just putting back what you've said in 
sysctl.conf
It looks like ip_forward is being reset by /etc/init.d/network when you 
pass argument STOP or RESTART (with the network STOPPED, how can there 
be forwarding?)
it does look like /etc/init.d/network START reruns any sysctl.conf 
settings, so its probably turning it back on when the network is 
(re)started if you're setting it in there.