Interoperability between Dell and Cisco: Rapid-PVST+
Today I am going to talk about the PVST+ as many of you already know. PVST+ is the advance version of PVST and stands for the Per VLAN spanning Tree Plus. As the name suggest you can have the you are creating STP for the VLANs. So if you have 3 VLANs in your network you have 3 different STP instances per VLAN in your LAN network.
Here today I am taking an example where i am taking Cisco and Dell switches in a LAN network and we are going to check the interoperability between the Cisco and Dell.
Below is the sample network topology showing the Cisco and Dell switches
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Fig 1.1- LAN network STP topology
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So in the above mentioned topology, we have 2 Cisco 3550 switches and connected with the Dell Force10 S60 switch where the end user is connected. The switches are in the distribution layers are Cisco 3550 switches and Dell switch is at access layer. We are going to configure Cisco Rapid PVST+ on Cisco 3550 switches. Here in the case, Cisco inter-switch links are dot1Q trunk carrying all VLAN traffic where VLAN 1 as native VLAN.
As an example we are taking Cisco D1 switch as a root bridge for VLAN 1, 11, 12 and 13. On switch A1 which is a Dell switch running with PVST+. As you see in the above mentioned topology, the post Gi0/43 is blocked for all VLANs.
Configurations on Cisco D1 Switch
!
interface FastEthernet0/2
interface FastEthernet0/2
description LINK 3 to Cisco-D2 Fa0/2
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/3
description LINK 1 to Force10 s60 Gi0/42
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface Vlan1 no ip address
!
interface Vlan11
interface Vlan11
ip address 11.11.11.1 255.255.255.0
!
interface Vlan12
ip address 12.12.12.1 255.255.255.0
ip address 12.12.12.1 255.255.255.0
!
interface Vlan13
interface Vlan13
ip address 13.13.13.1 255.255.255.0 !
!
Cisco-D1#sh spanning-tree summary
Switch is in rapid-pvst mode
Root bridge for: VLAN0001, VLAN0011, VLAN0012, VLAN0013
Extended system ID is enabled
Switch is in rapid-pvst mode
Root bridge for: VLAN0001, VLAN0011, VLAN0012, VLAN0013
Extended system ID is enabled
Configurations on Cisco D2 Switch
!
interface FastEthernet0/2
interface FastEthernet0/2
description LINK 3 to Cisco-D1 Fa0/2
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/3
description LINK 3 to s60 Gi0/43
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface Vlan1 no ip address
!
interface Vlan11
interface Vlan11
ip address 11.11.11.2 255.255.255.0
!
interface Vlan12
ip address 12.12.12.2 255.255.255.0
ip address 12.12.12.2 255.255.255.0
interface Vlan13
ip address 13.13.13.2 255.255.255.0
ip address 13.13.13.2 255.255.255.0
!
Cisco-D2#sh spanning-tree summary
Switch is in rapid-pvst mode
Root bridge for: VLAN0001, VLAN0011, VLAN0012, VLAN0013
Extended system ID is enabled
Configurations on Dell Force Access Switch
!
protocol spanning-tree pvst
no disable
vlan 1,11,12,13 bridge-priority 61440
no disable
vlan 1,11,12,13 bridge-priority 61440
!
interface GigabitEthernet 0/0 description access port for test
interface GigabitEthernet 0/0 description access port for test
no ip address
switchport
spanning-tree pvst edge-port bpduguard
switchport
spanning-tree pvst edge-port bpduguard
no shutdown
!
interface GigabitEthernet 0/42
description LINK 1 to Cisco 3550 D1
no ip address
portmode hybrid
switchport no shutdown
!
interface GigabitEthernet 0/43
interface GigabitEthernet 0/43
description LINK 2 to Cisco 3550 D2
no ip address
portmode hybrid
switchport
no shutdown
!
interface Vlan 1
!untagged GigabitEthernet 0/42-43
!
interface Vlan 11
!untagged GigabitEthernet 0/42-43
!
interface Vlan 11
no ip address
tagged GigabitEthernet 0/42-43
tagged GigabitEthernet 0/42-43
untagged GigabitEthernet 0/0
no shutdown
!
interface Vlan 12
no ip address
tagged GigabitEthernet 0/42-43
no ip address
tagged GigabitEthernet 0/42-43
no shutdown
!
interface Vlan 13
interface Vlan 13
no ip address
tagged GigabitEthernet 0/42-43
tagged GigabitEthernet 0/42-43
no shutdown
!
Dell Force10-A1#sh spanning-tree pvst | grep GigabitEthernet
!
VLAN 1
Dell Force10-A1#sh spanning-tree pvst | grep GigabitEthernet
Dell Force10-A1#sh spanning-tree pvst | grep GigabitEthernet
Port 172 (GigabitEthernet 0/42) is TYPE_INC Discarding
Port 173 (GigabitEthernet 0/43) is TYPE_INC Discarding
Port 173 (GigabitEthernet 0/43) is TYPE_INC Discarding
!
VLAN 11
Port 130 (GigabitEthernet 0/0) is disabled Discarding
Port 172 (GigabitEthernet 0/42) is root Forwarding
Port 173 (GigabitEthernet 0/43) is alternate Discarding
VLAN 11
Port 130 (GigabitEthernet 0/0) is disabled Discarding
Port 172 (GigabitEthernet 0/42) is root Forwarding
Port 173 (GigabitEthernet 0/43) is alternate Discarding
!
VLAN 12
Port 172 (GigabitEthernet 0/42) is root Forwarding
Port 173 (GigabitEthernet 0/43) is alternate Discarding
VLAN 12
Port 172 (GigabitEthernet 0/42) is root Forwarding
Port 173 (GigabitEthernet 0/43) is alternate Discarding
!
VLAN 13
Port 172 (GigabitEthernet 0/42) is root Forwarding Port 173 (GigabitEthernet 0/43) is alternate Discarding
VLAN 13
Port 172 (GigabitEthernet 0/42) is root Forwarding Port 173 (GigabitEthernet 0/43) is alternate Discarding
!
