12-30-2023 10:28 PM
I have configured four switches, two 3750 switches which are root for MST 1 and root for MST 2 (IPSwitch0 & IPSwitch1), the primary root is 24576 and the secondary root is 28672 plus the MST number for all three MSTs (MST 0, MST 1, and MST 2).
Switch0 is a 2960 and has joined the MST region, Switch1 is configured with the same MST configuration but refuses to join the MST region. It has elected itself as the root for all three MSTs:
Switch1 is not receiving any BPDUs on any of the trunk ports to IPSwitch1 or Switch0.
IPSwitch1 and Switch0 both show their directly connected ports to Switch1 are blocked because of a dispute. It is my understanding that a dispute is caused when either switch receives an inferior BPDU with the designated bit set.
I have also tried shutting all other ports other than the link on Gi0/1 to IPSwitch0 and the results do not change. I have also removed STP features Loop Guard and Backbone Fast with the same results.
Looking forward to any suggestions
12-31-2023 02:21 AM
Hi friend can you share the config of four SW
MHM
12-31-2023 08:25 AM
12-31-2023 03:43 PM
Friend
First happy new year
Now regarding your issue' the issue as I review your config is due to config defualt portfast in global mode with bpduguard.
This make port go to errdisable.
So remove portfast and bpduguard from global and config it only on port connect to host.
Check show interface status
See which port is errdisable
No shut these ports
Then check mst.
MHM
01-01-2024 04:27 AM
Hello
suggest the following:
Core switch 1
no spanning-tree vlan 30 priority x
no spanning-tree vlan 32 priority x
no spanning-tree vlan 30,32 forward-time x
no spanning-tree vlan 30,32 max-age x
spanning-tree mst 0,2 priority 0
spanning-tree mst 1 priority 4096
Core switch 2
no spanning-tree vlan 30 priority x
no spanning-tree vlan 32 priority x
no spanning-tree vlan 30,32 forward-time x
no spanning-tree vlan 30,32 max-age x
spanning-tree mst 0,2 priority 4096
spanning-tree mst 1 priority 0
All switch's
interface x/x
description TRUNKS
no spanning-tree vlan x port-priority x
switchport trunk allowed vlan all
spanning-tree link-type point-to-point
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide