Hitachi US7070447-001 manual Troubleshooting Bridging Issues

Draft Level—Hitachi Confidential

Bridging Concepts

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

US7070447-001, Rev 01 7-3