Get the IP of the website from which the request was made

I am creating a website say site1 form which i redirect to another website site2 . here i have to print the ip of the page form which it is requested i.e site1. i tried this but i it is printing the ip of site2 always i used

in site1

app.get('/re', function(req, res) {
  res.redirect('site2');
});

in site2

app.get('/', function(req, res) 
{
  res.send('Address track completed'+req.connection.remoteAddress)
});

thanks