Hitachi US7070447-001 Switch User Manual


 
Bridging Concepts
US7070447-001, Rev 01
7-3
Draft Level—Hitachi Confidential
If, on any given port, a bridge decides to keep a packet from another bridge
instead of the packet that it would send, it no longer transmits BPDU messages.
Basically, it drops out of the running because it realizes there is a better bridge for
the job. When the algorithm finally stabilizes, only one bridge on each segment
will transmit BPDUs on that segment. This bridge is known as the designated
bridge for that segment.
Finally, the bridges decide which ports are active, and which are blocking. With
Spanning Tree on, the ports go through the following Spanning Tree states:
Listening
Learning
Blocking or Forwarding
Troubleshooting Bridging Issues
Problem:
PC is moved to a different port on the switch. Users can no longer
ping me
.
Solution:
Wait for Spanning Tree to stabilize completely. The default STA timer is
15 seconds for the ports to go from ‘Listening’ to a ‘Forwarding’ state.
To verify the port state, type
vvp
You may also need to wait for the previous MAC entry to age out of the
bridge forwarding table. The default bridge aging timer is 300 seconds.
However, to expedite this process, ping the switch and it will immediately
replace the previous MAC entry with the new one.
To view the Bridge Forwarding table, type
vfwt
Verify that a static entry has not been created for this user.
To show static entries, type ‘
fl
If so, you will need to remove that entry from the static table.
To delete a static entry, type
delfl