Cabletron Systems Expansion module 9T122-08 User Manual

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9T122-08 Module Specific Information

Unknown&Broadcast Forwarding

DeÞnes how frames destined for unknown destination addresses (not in the
bridge database) and broadcast destination addresses are handled when the
frame is transmitted by the Token Ring interfaces. This Þeld is per bridge
interface.

For the FDDI interface, the frame cannot be changed. It is Þxed as a
transparent only (TP) network. Therefore, all unknown and broadcast frames
are sent onto FDDI as TP frames.

For the Token Ring interfaces, this Þeld is selectable. Table 3 describes what
choices are available and when.

Table 3. Unknown and Broadcast Forwarding Choices

Bridge Method

Unknown & Broadcast Forwarding Choices

TP -

Frames that are destined for an unknown destination

address (not in bridge database) or a broadcast destination
address are forwarded on to the Token Ring(s) as TP frames.
No translation for source routing is performed.

ARE -

Frames that are destined for an unknown destination

address (not in bridge database) or a broadcast destination
address are forwarded onto the Token Ring(s) as All Route
Explorer (ARE) frames. FDDI TP frames are translated to
this type of source routed frame.

STE -

Frames that are destined for an unknown destination

address (not in bridge database) or a broadcast destination
address are forwarded onto the Token Ring(s) as Spanning
Tree Explorer (STE) frames. FDDI TP frames are translated
to this type of source routed frame.

SRT (default)

ARE

(See ARE deÞnition above)

STE

(See STE deÞnition above). This is the default.

(See TP deÞnition above)