Lexmark IBM 9077 - Manual (Page 240)

222 IBM 9077 SP Switch Router: Get Connected to the SP Switch
When port 0 is plugged in again, it resumes and takes over port 1, which in
turn falls back to the blocked state, as the following screen shot proves:
We expect this to happen also with the one-ported ATM OC-12c 622Mbit
media card, so if two of them are put into a bridging group, this could be a
fault tolerant scenario.
7.2 ATM OC-12c Backbone - One Port
This setup is basically the same as using just one port of an ATM OC-3c card,
as described in Section 7.1.1, “ATM OC-3c Backbone - Using One Port” on
page 210.
grf16:/root brstat
Bridge Group bg1
Spanning Tree: Enabled
Designated Root: 32768 00:c0:80:84:8c:eb
Bridge ID: 32768 00:c0:80:96:38:68
Root Port: ga0180, Root Path Cost: 10
Topology Change Detected: No
Root Max Age: 20, Hello Time: 2, Forward Delay: 15
Bridge Max Age: 20, Hello Time: 2, Forward Delay: 15, Hold Time: 1
Path Desig Desig Desig
Interface Port ID Con State Cost Cost Bridge Port
--------- ------- --- ---------- ----- ----- ----------------------- -------
ga010 128 1 No Disabled 10
*ga0180 128 2 Yes Forwarding 10 0 32768 00:c0:80:84:8c:eb 128 2
Dump snapshot finished at Mon Jun 15 20:01:51 1998
grf16:/root brstat
Bridge Group bg1
Spanning Tree: Enabled
Designated Root: 32768 00:c0:80:84:8c:eb
Bridge ID: 32768 00:c0:80:96:38:68
Root Port: ga010, Root Path Cost: 10
Topology Change Detected: No
Root Max Age: 20, Hello Time: 2, Forward Delay: 15
Bridge Max Age: 20, Hello Time: 2, Forward Delay: 15, Hold Time: 1
Path Desig Desig Desig
Interface Port ID Con State Cost Cost Bridge Port
--------- ------- --- ---------- ----- ----- ----------------------- -------
*ga010 128 1 Yes Forwarding 10 0 32768 00:c0:80:84:8c:eb 128 1
ga0180 128 2 Yes Blocking 10 0 32768 00:c0:80:84:8c:eb 128 2
Dump snapshot finished at Mon Jun 15 20:02:03 1998