Build a loop (fibre, ring) between Network Core (Stack : 2 x 9300) and many Cisco Switchs (2960-X)

[CERKYR]

Hello,

I build a new network loop.

1st :  I have 2 switchs linked with stack (9300), and 8 GBIC per switch.
2nd : I have many other switchs with 2 GBIC per switch.

I create a fiber network : 

-----

9300_Nb1 (gbic_3) >>

gbic_25 : 2960-X  :  gbic_27 >>

gbic_25 : 2960-X  :  gbic_27 >>

gbic_25 : 2960-X  :  gbic_27 >>

9300_Nb2 (gbic_3)

------

9300_Nb1  <<STACK>>  9300_Nb2

I try to configure the spanning-tree with many commands; but each time I close the loop, the CPU of the STACK go to 100 % after 30 seconds; very bad.

What are the mandatory commands to resolve the problem ?

Regards,

[CERKYR]

Actions :
1st : Update all the firmware of the 2960-X
2nd : Command on all the 5 switches:

---

enable
conf t
spanning-tree bpduguard enable
spanning-tree mode rapid-pvst
spanning-tree VLAN 2,3,4,5

---

On the first switch 9300 :
spanning-tree vlan 2-5 root primary

---

On 9300_Nb1 (port gbic_3) :
spanning-tree vlan 2-5 port-priority 64

---

On the other switches 2960-x :
spanning-tree vlan 2-5 root secondary

---

on each 2960-X (ports gbic 25 and 27) :
spanning-tree vlan 2-5 port-priority 128

---

What the missing or wrong commands ?

[CERKYR]

It seems that this command can apply the priority to on switch : 

spanning-tree vlan vlan-id priority priority

[CERKYR]

My feeling is that this Trunk port is not "Blocked" automatically.
9300_Nb2 (gbic_3)
Why ?
Because the other Trunk ports are not in "Forwarding" mode ?
How to do that ?

[balaji.bandi]

Do you have any high-level network diagram and share the configuration ?

[CERKYR]

Hello,

I can share, tomorrow, the configuration of each Trunk Port, for each switch.

----

The very simple diagram is like that

9300_Nb1 <<STACK>> 9300_Nb2
I create a fiber network :
-----
9300_Nb1 (gbic_3) >> << gbic_25 2960-X_Nb1 gbic_27 >> << gbic_25 2960-X_Nb2 gbic_27 >> << gbic_25 2960-X_Nb3 gbic_27 >>XXX 9300_Nb2 (gbic_3)
------

Without the "shut" XXX on the port " 2960-X_Nb3 : gbic_27 ",
I have a lot of Broadcast Storm ...

Regards,

[CERKYR]

Hello,

I can share, tomorrow, the configuration of each Trunk Port, for each switch.

----

The very simple diagram is like that

9300_Nb1 <<STACK>> 9300_Nb2
I create a fiber network :
-----
9300_Nb1 (gbic_3) >> << gbic_25 2960-X_Nb1 gbic_27 >> << gbic_25 2960-X_Nb2 gbic_27 >> << gbic_25 2960-X_Nb3 gbic_27 >>XXX 9300_Nb2 (gbic_3)
------

Without the "shut" XXX on the port " 2960-X_Nb3 : gbic_27 ",
I have a lot of Broadcast Storm ...

Regards,

[CERKYR]

description Trunk vers SW2
switchport trunk native vlan 50
switchport trunk allowed vlan 50,51,52,53,54
switchport mode trunk
storm-control broadcast level 10.00
spanning-tree portfast
spanning-tree bpdufilter enable
spanning-tree bpduguard enable
spanning-tree guard loop
spanning-tree vlan 50,51,52,53,54 port-priority 64