11-22-2021 11:41 PM
Spanning tree was configured and enabled on C1111 router, but show spanning tree shows no spanning tree information as below. Does anyone know what the issue is and how to fix it? Thank you.
11-24-2021 12:29 AM - edited 11-24-2021 12:30 AM
Hello
Just noticed you have no interfaces in either of the vlans the two ports that are active are in vlan 1 and that’s admin down either assign one of the ports to those vlans or enable vlan1
11-24-2021 01:28 AM
11-24-2021 03:33 AM
Hello
@WilsonCheng wrote:
vlan 599 and vlan 990 are on trunk port g0/1/0 already. We don't need to
assign them to the access port.
Granted but we are discussing a rtr here not a definitive switching device, we could be well looking at buggy software,
You could try reapplying or changing the stp mode to see if that helps and as vlan 1 is being allowed over the trunk enable it just to see?
Gi0/1/1, Gi0/1/2 = down state
g0/1/0 = trunk (native vlan 990)
gig0/0/0 = i assume is routed
gig0/1/3 < ???
11-24-2021 05:16 AM
I think this router does not support Spanning-Tree. It does support layer 3 port-channel, but in the documentation, it does not mention anything of spanning-tree or any of 802.1D, 802.1W, 802.1s standards on the LAN ports, it does not even support layer 2 port-channels.
I do have the C1111-4p and I was surprised when I wanted to do layer 2 port-channel on the LAN ports and it was not supported.
11-24-2021 05:50 AM
Hello @emurray
If this is correct that would do be the reason; I’m surprised it lets you create l2 features if it doesn’t support them.
11-24-2021 05:59 AM - edited 11-24-2021 06:14 AM
In prior images, the commands were not there. I just notice that in my latest upgrade, I have active/passive options for LACP mode in channel-group spanning-tree but they were not there in version 16, and last year when I tried, I couldn't find any of the commands available. Now only has LACP options, It does not have PAGP options.
I found in my research last year, a thread here stating the router does not have the power to do all those functions.
Maybe version 17 have the commands now, but is still incapable of supporting spanning-tree
07-31-2024 12:11 AM
I guess this relate to "vlan database".
To check it, execute following commands from global command prompt.
vlan database
show
07-31-2024 06:46 AM
That is a strange thing about the C1111. If I look at show span then I don't get any output until I activate rapid-PVST as shown here.
R1#show vlan brie
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Gi0/1/0, Gi0/1/1, Gi0/1/2, Gi0/1/3, Gi0/1/4, Gi0/1/5
3 Firewall-Interconnect active Gi0/1/6
R1#show span
No spanning tree instance exists.
R1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#spanning-tree mode rapid-pvst
Warning: Changing STP mode can disrupt the traffic and make system unstable
Recommend to change STP mode only during maintenance window
R1(config)#do show span
G0:VLAN0003
Spanning tree enabled protocol rstp
Root ID Priority 32771
Address f80f.6f6a.40f1
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32771 (priority 32768 sys-id-ext 3)
Address f80f.6f6a.40f1
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/1/6 Desg LRN 4 128.15 P2p
Gi0/1/7 Desg LRN 4 128.16 P2p
07-31-2024 06:14 PM
It seems to be very strange because the initial post of this thread has following
router#sh spanning-tree sum
Switch is in rapid-pvst mode
If you have output of "show spanning-tree summary" before entering command for rapid-pvst mode, it may help to clarify the situation.
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide