Hello everyone,
We have some strange things going on in the network, I hope your suggestions will help to find the right path for me
Yesterday 3 edge switches in the network started throwing Loop-detected messages and the uplink ports went into err-disabled state
I issued the no keepalive command, and it did the trick, everything is ok
However, when I run sh storm control broadcast on the uplink ports of these 3 switches, I can see 0,56%-0,89% broadcasts. I have checked other switches in the network, they never detected a loop and broadcast level is 0%
One of these 3 switches is connected to our Root Bridge, I checked storm control on the port of the Root Bridge going to this switch - it is 0%. However, as I told before, the other end the link is showing some broadcasts
We have a ring topology in the network, running MST, no loops are detected.
When I issue sh spanning-tree detail on the affected switch (Which is connected to the Root Bridge), I can see this:
MST1 is executing the mstp compatible Spanning Tree protocol
Bridge Identifier has priority 32768, sysid 1, address 0019.aacb.b200
Configured hello time 2, max age 20, forward delay 15, transmit hold-count 6
Current root has priority 24577, address 0019.554a.b380
Root port is 26 (FastEthernet1/0/24), cost of root path is 200000
Topology change flag not set, detected flag not set
Number of topology changes 39 last change occurred 00:05:11 ago
from FastEthernet1/0/24
Fast Ethernet 1/0/24 is a root port
On the Root Bridge, when I issue the same comand, I get this:
MST1 is executing the mstp compatible Spanning Tree protocol
Bridge Identifier has priority 24576, sysid 1, address 0019.554a.b380
Configured hello time 2, max age 20, forward delay 15, transmit hold-count 6
We are the root of the spanning tree
Topology change flag not set, detected flag not set
Number of topology changes 466 last change occurred 00:06:44 ago
from StackPort1
Dont really understand, why is it showing StackPort1.
Is there any way I can track down which port cause Topology Change?
Can the small broadcasts on the switch and loop-detect have any relation to each other?
How is it possible that Loop-detection happened only on 3 switches in the network, and these switches are Edge switches?
Thank you!
