IP address kept returning 0.0.0.0 ?? why?

[eluser]Unknown[/eluser]
why is my ip address kept returning 0.0.0.0 ? i checked google and my ip is

164.11.x.x

can anyone explained what's going on? or is there anything I missed before calling this function? is it because my system running on localhost?

Code:

function check_ip()
{
  echo $this->input->ip_address();
}