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Encapsulation Header
S=Xmitting Rbridge
D=Rcving Rbridge
pt=“transit”
hop count
original pkt (including L2 hdr)
Outer L2 hdr must not confuse bridges
So it’s just like it would be if the Rbridges were routers
Need special layer 2 destination address
for unknown or multicast layer 2 destinations
can be L2 multicast, or any L2 address provided it never gets used as a source address
PPT Version