Changing /proc entries with sysctl

Using sysctl and /etc/sysctl.conf

 # sysctl net.ipv4.ip_forward         # just like
 1                                    # cat /proc/net/ipv4/ip_forward

 # sysctl -w net.ipv4.ip_forward=0    # just like
                                      # echo 0 > /proc/net/ipv4/ip_forward


 # cat /etc/sysctl.conf
 net.ipv4.ip_forward = 0
 net.ipv4.conf.eth0.accept_redirects = 0

 # sysctl -p /etc/sysctl.conf         # apply all settings in sysctl.conf