Support HSRP and Spanning-tree

[Nam Nguyen Thanh]

Dear Team.

Our system are using 02 switch2960, 02 router2921(EHWIC-4ESG).

We have 5 vlan on switch and router, we use HSRP and Spanning-tree. When i plug cable with green color (Fe0/0/0 and Fe0/2/0), The system was loop. IOS c2900-universalk9-mz.SPA.152-4.M4.bin.

Please view topology in attach file and give me some advise!

Thank you.

[matthew-frederick]

Make sure you don't have spanning tree portfast enabled on the ports. Can you post the configurations for Fe0/0/0 and Fe0/2/0?

[Nam Nguyen Thanh]

Dear Matthew.

On router 2921:

interface FastEthernet0/0/0
 switchport mode trunk
 no ip address
!
interface FastEthernet0/2/0
 switchport mode trunk
 no ip address

Please help me check!

Thanks.

[Emmanouil Patiniotakis]

Plaese provide the rest of the config aw well...

[Nam Nguyen Thanh]

Dear Team.

I just update new topology with the same config.

The configurations for Fe0/0/0 and Fe0/2/0 move to Gi0/1/0 and Gi0/0/0.

interface GigabitEthernet0/1/0
 switchport mode trunk
 no ip address

interface GigabitEthernet0/0/0
 switchport mode trunk
 no ip address

Thank you.

[Robert Falconer]

Can you post more of the configurations on the switches and routers? Information on each link/interface that you have listed would be helpful.

Do the switches have a trunk connection between them?