I have never seen the " 'do' -> function() { "in a route before.

Maybe try without,

Route::get('test_server2', array('before' => 'test_filter', function() {
    return 'After filter';
}));

There are no special configs needed to use filters on either server, it should work on both in the same way.

The "do" thing is OK. I saw it somewhere and it's an alternative way to specify it.

I've tried removing it as you suggested but it didn't work. I prepared this route to show a very simple example that isn't working on a server. I have a large application with many different routes and filters that never get applied, so I tried to simplify as much as possible.

Does anyone know why the filters may not get executed?