CML Spanning-Tree Lab Issues

[etodust]

I'm doing a simple practice lab. The lab is designed to not give you all the information you need. I am trying to do a lab a day in preparation for getting my CCNP. (Still a ways off) This is also my first experience with CML and the IOSvL2 nodes. I'm hoping that my CML purchase wasn't a mistake.

Problem: All switches consider themselves to be the root bridge.

DLS1 is set to root primary, DLS2 is set to root secondary. I'm using VTP, and all VLANs created on DLS1 propagated appropriately to the other switches.

My first instinct is that these IOSvL2 nodes don't do what I think they do. If someone could confirm the difference between using this and using a virtualized Catalyst 2960, and what problems I might run into. CML only gives us a single option for managed switches. All I want to do is practice CCNP level networking, but Cisco has made it so difficult and expensive to get this stuff setup. I finally got CML setup on VMware, and now It seems like its gonna be a long road of headaches.

I would greatly appreciate any help on this. I would be happy to provide more information or logs if necessary. I feel like this problem may just stem from a fundamental misunderstanding of CML.

Thanks!

[balaji.bandi]

Problem: All switches consider themselves to be the root bridge.

Never seen this issue  - i am using vios_l2 Software (vios_l2-ADVENTERPRISEK9-M), Version 15.2

it works as expected. (if each switch is acting root, meaning there may be some issue or they do not participate in STP.

post all the device show run and show spann

[etodust]

DLS1#show run
Building configuration...

Current configuration : 2886 bytes
!
! Last configuration change at 01:31:20 UTC Sun Oct 3 2021
!
version 15.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
service compress-config
!
hostname DLS1
!
boot-start-marker
boot-end-marker
!
!
!
no aaa new-model
!
!
!
!
!
!
!
!
ip cef
no ipv6 cef
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
spanning-tree vlan 100,200 priority 24576
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface GigabitEthernet0/0
switchport mode dynamic desirable
negotiation auto
!
interface GigabitEthernet0/1
switchport mode dynamic desirable
negotiation auto
!
interface GigabitEthernet0/2
switchport mode dynamic desirable
negotiation auto
!
interface GigabitEthernet0/3
shutdown
negotiation auto
!
ip forward-protocol nd
!
ip http server
ip http secure-server
!
ip ssh server algorithm encryption aes128-ctr aes192-ctr aes256-ctr
ip ssh client algorithm encryption aes128-ctr aes192-ctr aes256-ctr
!
!
!
!
!
!
control-plane
!
banner exec ^C
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************^C
banner incoming ^C
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************^C
banner login ^C
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************^C
!
line con 0
line aux 0
line vty 0 4
!
!
end

DLS1#show span

VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 28772
Address 5254.000e.cba7
Cost 4
Port 1 (GigabitEthernet0/0)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 5254.001d.f206
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Root FWD 4 128.1 P2p
Gi0/1 Desg FWD 4 128.2 P2p
Gi0/2 Desg FWD 4 128.3 P2p

VLAN0100
Spanning tree enabled protocol ieee
Root ID Priority 24676
Address 5254.001d.f206
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 24676 (priority 24576 sys-id-ext 100)
Address 5254.001d.f206
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 4 128.1 P2p
Gi0/1 Desg FWD 4 128.2 P2p
Gi0/2 Desg FWD 4 128.3 P2p

VLAN0200
Spanning tree enabled protocol ieee
Root ID Priority 24776
Address 5254.001d.f206
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 24776 (priority 24576 sys-id-ext 200)
Address 5254.001d.f206
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 4 128.1 P2p
Gi0/1 Desg FWD 4 128.2 P2p
Gi0/2 Desg FWD 4 128.3 P2p

DLS2#show run
Building configuration...

Current configuration : 2886 bytes
!
! Last configuration change at 01:35:49 UTC Sun Oct 3 2021
!
version 15.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
service compress-config
!
hostname DLS2
!
boot-start-marker
boot-end-marker
!
!
!
no aaa new-model
!
!
!
!
!
!
!
!
ip cef
no ipv6 cef
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
spanning-tree vlan 100,200 priority 28672
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface GigabitEthernet0/0
switchport mode dynamic desirable
negotiation auto
!
interface GigabitEthernet0/1
switchport mode dynamic desirable
negotiation auto
!
interface GigabitEthernet0/2
switchport mode dynamic desirable
negotiation auto
!
interface GigabitEthernet0/3
shutdown
negotiation auto
!
ip forward-protocol nd
!
ip http server
ip http secure-server
!
ip ssh server algorithm encryption aes128-ctr aes192-ctr aes256-ctr
ip ssh client algorithm encryption aes128-ctr aes192-ctr aes256-ctr
!
!
!
!
!
!
control-plane
!
banner exec ^C
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************^C
banner incoming ^C
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************^C
banner login ^C
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************^C
!
line con 0
line aux 0
line vty 0 4
!
!
end

DLS2#show span

VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 24676
Address 5254.001d.f206
Cost 4
Port 1 (GigabitEthernet0/0)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 5254.000e.cba7
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Root FWD 4 128.1 P2p
Gi0/1 Altn BLK 4 128.2 P2p
Gi0/2 Desg FWD 4 128.3 P2p

VLAN0100
Spanning tree enabled protocol ieee
Root ID Priority 28772
Address 5254.000e.cba7
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 28772 (priority 28672 sys-id-ext 100)
Address 5254.000e.cba7
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 4 128.1 P2p
Gi0/1 Desg FWD 4 128.2 P2p
Gi0/2 Desg FWD 4 128.3 P2p

VLAN0200
Spanning tree enabled protocol ieee
Root ID Priority 28872
Address 5254.000e.cba7
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 28872 (priority 28672 sys-id-ext 200)
Address 5254.000e.cba7
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 4 128.1 P2p
Gi0/1 Desg FWD 4 128.2 P2p
Gi0/2 Desg FWD 4 128.3 P2p

ALS1#SHOW RUN
Building configuration...

Current configuration : 2739 bytes
!
! Last configuration change at 01:29:08 UTC Sun Oct 3 2021
!
version 15.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
service compress-config
!
hostname ALS1
!
boot-start-marker
boot-end-marker
!
!
!
no aaa new-model
!
!
!
!
!
!
!
!
ip cef
no ipv6 cef
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface GigabitEthernet0/0
negotiation auto
!
interface GigabitEthernet0/1
negotiation auto
!
interface GigabitEthernet0/2
negotiation auto
!
interface GigabitEthernet0/3
shutdown
negotiation auto
!
ip forward-protocol nd
!
ip http server
ip http secure-server
!
ip ssh server algorithm encryption aes128-ctr aes192-ctr aes256-ctr
ip ssh client algorithm encryption aes128-ctr aes192-ctr aes256-ctr
!
!
!
!
!
!
control-plane
!
banner exec ^C
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************^C
banner incoming ^C
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************^C
banner login ^C
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************^C
!
line con 0
line aux 0
line vty 0 4
!
!
end

ALS1#show span

VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 24676
Address 5254.001d.f206
Cost 4
Port 2 (GigabitEthernet0/1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 5254.000f.7c79
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 4 128.1 P2p
Gi0/1 Root FWD 4 128.2 P2p
Gi0/2 Altn BLK 4 128.3 P2p

VLAN0100
Spanning tree enabled protocol ieee
Root ID Priority 32868
Address 5254.000f.7c79
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32868 (priority 32768 sys-id-ext 100)
Address 5254.000f.7c79
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/1 Desg FWD 4 128.2 P2p
Gi0/2 Desg FWD 4 128.3 P2p

VLAN0200
Spanning tree enabled protocol ieee
Root ID Priority 32968
Address 5254.000f.7c79
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32968 (priority 32768 sys-id-ext 200)
Address 5254.000f.7c79
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/1 Desg FWD 4 128.2 P2p
Gi0/2 Desg FWD 4 128.3 P2p

ASL2#show run
Building configuration...

Current configuration : 2739 bytes
!
! Last configuration change at 01:28:57 UTC Sun Oct 3 2021
!
version 15.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
service compress-config
!
hostname ASL2
!
boot-start-marker
boot-end-marker
!
!
!
no aaa new-model
!
!
!
!
!
!
!
!
ip cef
no ipv6 cef
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface GigabitEthernet0/0
negotiation auto
!
interface GigabitEthernet0/1
negotiation auto
!
interface GigabitEthernet0/2
negotiation auto
!
interface GigabitEthernet0/3
shutdown
negotiation auto
!
ip forward-protocol nd
!
ip http server
ip http secure-server
!
ip ssh server algorithm encryption aes128-ctr aes192-ctr aes256-ctr
ip ssh client algorithm encryption aes128-ctr aes192-ctr aes256-ctr
!
!
!
!
!
!
control-plane
!
banner exec ^C
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************^C
banner incoming ^C
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************^C
banner login ^C
**************************************************************************
* IOSv is strictly limited to use for evaluation, demonstration and IOS *
* education. IOSv is provided as-is and is not supported by Cisco's *
* Technical Advisory Center. Any use or disclosure, in whole or in part, *
* of the IOSv Software or Documentation to any third party for any *
* purposes is expressly prohibited except as otherwise authorized by *
* Cisco in writing. *
**************************************************************************^C
!
line con 0
line aux 0
line vty 0 4
!
!
end

ASL2#show span

VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 24676
Address 5254.001d.f206
Cost 4
Port 3 (GigabitEthernet0/2)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 5254.000b.491e
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 4 128.1 P2p
Gi0/1 Desg FWD 4 128.2 P2p
Gi0/2 Root FWD 4 128.3 P2p

VLAN0100
Spanning tree enabled protocol ieee
Root ID Priority 32868
Address 5254.000b.491e
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32868 (priority 32768 sys-id-ext 100)
Address 5254.000b.491e
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/1 Desg FWD 4 128.2 P2p
Gi0/2 Desg FWD 4 128.3 P2p

VLAN0200
Spanning tree enabled protocol ieee
Root ID Priority 32968
Address 5254.000b.491e
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32968 (priority 32768 sys-id-ext 200)
Address 5254.000b.491e
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/1 Desg FWD 4 128.2 P2p
Gi0/2 Desg FWD 4 128.3 P2p

[etodust]

I am running the same version as you, vios_12-ADVENTERPRISEK9-M

[etodust]

NOTE: Native VLAN 1 doesn't appear to have this issue. All devices state that they are the root bridge for VLAN 100 and 200.

[balaji.bandi]

I do not see the config consistency in all switches:

1. I do not see any VTP config, which can replicate the VLAN config to other switches :

2. All the switches connecting each other port should be a trunk to pass the VLAN information.

I have provided the solution to work, but I would suggest learning so you understand better and fix the issue, so you know the mistakes.

The below document explain you 

https://www.ciscopress.com/articles/article.asp?p=2181837&seqNum=8

https://networklessons.com/switching/cisco-dtp-dynamic-trunking-protocol-negotiation

happy labbing !!

[etodust]

I configured VTP domain, password, and version on all switches. If I hadn't, then how would the VLANs have propagated to the other switches. I only configured VLANs on DLS1. It seems like I am possibly running into a glitch.

[etodust]

I've redone this lab over and over, with the same result. All switches consider themselves the root bridge for VLANs 100, and 200. VLAN 1 behaves normally in regards to STP.

Note: balaji.bandi was wrong about me not having VTP configured. VTP configurations are not shown in the running-config.

[etodust · Accepted solution]

For anyone wondering, I found the problem. I did not configure encapsulation mode.

After configuring dot1q for all active ports, root bridge is now on a single switch as it should be.

Never give up!