STP issue how to solve?

[Cyberurmel]

hI;

i have this issue :

OS 6450 several and DSS 6900 Switches ..normally works all fine

6.7.2.102 R07 FW

Per Vlan Spanning Tree is enforced !! (1x1 mode)
INACTIVE Spanning Tree Parameters for Flat Mode
Spanning Tree Status : ON,
Protocol : IEEE Rapid STP,
Priority : 32768 (0x8000),
TxHoldCount : 3,
System Max Age (seconds) = 20,
System Forward Delay (seconds) = 15,
System Hello Time (seconds) = 2

Now saw lots of

STP info Topology changed on VLAN/STP id x (different vlans)

Couldnt find any uplink which should flapping ..

how i can determine where this issue has its ground?

thanks a lot
Regards

[Gleylancer]

There is a myriad of reasons that could cause this, misconfiguration and Network Loops being the most common. One way of approaching this is to look for lots of mac moves to and from a single port.

[Cyberurmel]

Hi and thx first ..
and have you a hint for me how to search?