Ethernet Receive Filter

• Perfect matches: chip has room for a few addresses (e.g. 16 DEC Tulip), either unicast or multicast, if not many subscriptions, all is perfect

• Hashing scheme:

  • compute H(dest MAC address), where 0 <= H( ) <= n
  • if multicast_bit_vector[H( )] is ‘1’, accept
  • n is often 64 (512 for DEC Tulip)

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