Cabletron Systems SPECTRUM, User Manual

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FDDI Management
4-26 Viewing the Station List
Upstream MAC
Displays the hardware address of the node’s nearest upstream neighbor. Note
that the addresses displayed in this field also respond to any change in display
mode from MSB to Canonical, or vice versa.
Vendor
Displays the name of the vendor that manufactured the device, as determined by
the first three bytes of the MAC address.
Node Class
Indicates the node type: either station or concentrator.
Topology
Indicates the node’s current MAC configuration topology; possible states are:
Thru The ring is operating normally, with no cable breaks or
bad nodes directly upstream or downstream of the
selected node: the primary path enters the A port and
emerges from the B port, and is currently active; the
secondary path enters the B port and emerges from the A
port, and is not currently in use.
Wrapped The node is wrapped, due to a cable break, a bad station,
or management action; the secondary path has been
wrapped into the primary path to restore the ring.
Isolated The node is isolated from the ring; a node in this state
will be the only one displaying in the station list.
A-A Twisted The ring is in a twisted configuration, because the node’s
A port has been connected to another A; by necessity,
somewhere on the ring a B port is connected to another
B, and a third station has both an A—>A and a B—>B
connection. The ring can operate normally in a twisted
condition, but the station with both an A—>A and B—>B
connection is isolated from the primary ring and residing
alone on the secondary ring.
A-A Twisted,
Wrapped
The ring is twisted due to an A—>A connection on this
node, as described above; the ring is also wrapped. Note
that the wrap condition brings the node with both the
A—>A and B—>B connection back into contact with the
rest of the stations on the ring, since the secondary ring
has become part of the primary ring.
B-B Twisted The ring is in a twisted configuration, because the node’s
B port has been connected to another B; again, by
necessity, somewhere on the ring an A port has been
connected to another A, and a third station has both and
A—>A and a B—>B connection. The ring can operate