stop icmp6 traffic

[A_(_dot_)_Parazzini_(_at_)_sirtisistemi_(_dot_)_it]

Hi all,
my i386 3.8 box generates this kind of traffic:

:: > ff02::1:ff96:b73f:
  icmp6: neighbor sol: who has fe80::260:97ff:fe96:b73f
fe80::260:97ff:fe96:b73f > ff02::1:ff96:b73f:
  HBH icmp6: multicast listener report max resp delay:
  0 addr: ff02::1:ff96:b73f [hlim 1]
fe80::260:97ff:fe96:b73f > ff02::2:7f01:7728:
  HBH icmp6: multicast listener report max resp delay:
  0 addr: ff02::2:7f01:7728 [hlim 1]

Is it possible to stop it (without pf) ?

Thanks.
Andrea


ifconfig:
lo0: flags=8049 mtu 33224
      groups: lo
      inet 127.0.0.1 netmask 0xff000000
      inet6 ::1 prefixlen 128
      inet6 fe80::1%lo0 prefixlen 64 scopeid 0x6
xl0: flags=8843 mtu 1500
      lladdr 00:60:97:96:b7:3f
      media: Ethernet 10baseT (10baseT half-duplex)
      status: active
      inet6 fe80::260:97ff:fe96:b73f%xl0 prefixlen 64 scopeid 0x1
pflog0: flags=0<> mtu 33224
pfsync0: flags=0<> mtu 1348
enc0: flags=0<> mtu 1536

/etc/rc.conf: default
/etc/rc.conf.local: empty
 /etc/sysctl.conf: default
/etc/hostname.xl0: only "up"