WNDR4500 sends strange UDP packets to port 7423

[wndr4500user]

Hi,
I have a netgear WNDR4500 updated with the lastest firmware 1.0.1.6. The router sends every 3 seconds these UDP packets on my LAN :

# tcpdump -i eth0 -n

10:22:30.204378 IP 192.168.1.1.32771 > 255.255.255.255.7423: UDP, length 173
10:22:33.264477 IP 192.168.1.1.32771 > 255.255.255.255.7423: UDP, length 173
10:22:36.324536 IP 192.168.1.1.32771 > 255.255.255.255.7423: UDP, length 173
10:22:39.384636 IP 192.168.1.1.32771 > 255.255.255.255.7423: UDP, length 173
10:22:42.444735 IP 192.168.1.1.32771 > 255.255.255.255.7423: UDP, length 173
10:22:45.504755 IP 192.168.1.1.32771 > 255.255.255.255.7423: UDP, length 173
10:22:48.564854 IP 192.168.1.1.32771 > 255.255.255.255.7423: UDP, length 173
10:22:51.624913 IP 192.168.1.1.32771 > 255.255.255.255.7423: UDP, length 173
.... (and so on)

1) What is it ?
2) Is there a way to disable it ? (I have already disabled the "Media Server" and "UPnP" but the router is still sending these packets)
3) Do you have the same issue ?


Thanks