Device-level Group Management Issues (cont'ed)

• • How to fix:
  • • Set up “multicast” filter appropriately.
    • • preferred if possible.
    • Change the mode to “ALLMULTI” (or “PROMISC”) mode if dev->mc_count is not zero.
    • • Several drivers were fixed by this way.
      • Note: This will result in the device entering “ALLMULTI” (or event “PROMISC”) mode because IPv6 stack joins at least 2 multicast addreses.
      • • all-node multicast address
        • solicited node multicast address
      • Note 2: Even a rich device usually needs this approach as well in the case of the group size exceeds its maximium group filter size.