This read-write enumerated integer enables or disables dual mode, in which the bridge translates a Token Ring broadcast or multicast packet into both Ethernet and IEEE 802.3 SNAP frame formats simultaneously whenever the destination format hasn't yet been learned. An administrator enables this to ensure broadcast and multicast traffic reaches both legacy Ethernet and SNAP-framed hosts during the period before the bridge has learned each host's specific format. For example, during initial deployment of a mixed-format segment before the bridge has built up its learned-address table, the admin enables dual mode to guarantee broadcasts reach all hosts regardless of their frame format.