Hello Community,
I have Cisco Catalyst Swicth 2950T-24 and the following scenario:
Port fa 0/1 : Trunk VLANs 10,20,30 (Providing trunk access to another remote switch in the network in order to re-distribute to customer)
Port fa 0/2: Access VLAN 10 (Customer)
Port fa 0/3: Access VLAN 20 (Customer)
Port 0/4: Access VLAN 30 (Customer)
Port 0/23 : Trunk 10,20,30 (Upstream Primary)
Port 0/24: Trunk 10,20,30 (Upstream Secondary)
Below is the configuration sample:
spanning-tree mode pvst
no spanning-tree optimize bpdu transmission
spanning-tree extend system-id
spanning-tree uplinkfast
interface FastEthernet0/1
description To_Another_Swicth
switchport trunk allowed vlan 10,20,30
switchport mode trunk
!
interface FastEthernet0/2
description Customer_A
switchport access vlan 10
switchport mode access
!
interface FastEthernet0/3
description Customer_B
switchport access vlan 20
switchport mode access
!
interface FastEthernet0/3
description Customer_C
switchport access vlan 30
switchport mode access
!
interface FastEthernet0/23
description Link_to_Upstream_Swicth_Primary
switchport trunk allowed vlan 10,20,30
switchport mode trunk
!
interface FastEthernet0/24
description Link_to_Upstream_Swicth_Secondary
switchport trunk allowed vlan 10,20,30
switchport mode trunk
spanning-tree cost 20
!
Problem:
Whenever I enable the fa 0/24, link to another switch connected from fa 0/1 becomes unstable. Please help me to accomplish to set fa 0/23 as Primary Upstream port and fa 0/24 as secondary for backup.
Any help will be highly appreciated. Thanks in advance.
