Is CHANGE_WIFI_MULTICAST_STATE permission and use of WifiManager.MulticastLock required to receive multicast packets on Android? -

i have test app i'm using demonstrate whether or not multicast traffic making android device. i'm seeing behavior appears contradict google's documentation here , here implies 2 prerequisites need in place in order app receive multicast traffic:

1. acquire multicastlock
2. add change_wifi_multicast_state permission app's manifest

my app able receive multicast traffic without either of these items in place. below code snippet sets multicast socket receiving data.

multicastsocket multicastreceivesocket = new multicastsocket( 18200 ); multicastreceivesocket.joingroup( inetaddress.getbyname( "232.232.232.232" ) );  byte[] buffer = new byte[ 65536 ]; datagrampacket packet = new datagrampacket( buffer, buffer.length ); multicastreceivesocket.receive( packet ); 

should happening? should able receive multicast packets without either of 2 prerequisites in place? noticed multicastlock documentation says:

normally wifi stack filters out packets not explicitly addressed device

does mean behavior different 1 device another? i'm testing app on samsung galaxy note4 (model sm-n910t) running android version 4.4.4. clarification on issue appreciated.

wifimanager.multicastlock when acquired, modify state of wifi interface on device (gobally), allow apps receive multicast traffic. app need change_wifi_multicast_state permission if app wants acquire lock.

in case, if multicast traffic received without acquiring lock, must mean either

(1) other app has acquired lock, due which, interface parsing/filtering , delivering multicast packets also.

or

(2) manufacturer of device ignored android api while developing device, , interface delivers multicast traffic.

the description of api not force manufacturers allow multicast traffic when app has acquired lock.

regardless, apps must acquire lock if want reliably receive multicast traffic.