"Vlans in spanning tree forwarding state and not pruned" empty on Nexus 5600 switch?

[michaelbs]

Dear all,

I've connected one Cisco Nexux 5672 switch to our Catalyst 3750 core using a trunk link on both sides which allows all vlans and has vlan 1 configured as native vlan.

When issuing the "show interface trunk" command on the Nexus device, the line "Vlans in spanning tree forwarding state and not pruned" does not show any vlans where I would expect VLAN 1:

sw-rz-5672-01# show interface trunk

--------------------------------------------------------------------------------
Port          Native  Status        Port
              Vlan                  Channel
--------------------------------------------------------------------------------
Eth1/1        1       trunking      --

--------------------------------------------------------------------------------
Port          Vlans Allowed on Trunk
--------------------------------------------------------------------------------
Eth1/1        1-4094

--------------------------------------------------------------------------------
Port          Vlans Err-disabled on Trunk
--------------------------------------------------------------------------------
Eth1/1        none

--------------------------------------------------------------------------------
Port          STP Forwarding
--------------------------------------------------------------------------------
Eth1/1        1

--------------------------------------------------------------------------------
Port          Vlans in spanning tree forwarding state and not pruned
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
Port          Vlans Forwarding on FabricPath
--------------------------------------------------------------------------------
Eth1/1        None

When issuing this on Catalyst switches, the line always shows the VLANs allowed on the trunk. We are not using VTP in our Network. Does it indicate a problem that the Nexus Switch Shows no information here? The Nexus Switch has another active Access port in VLAN 1!

Thanks,
Michael

[BenBen]

Hi Michael,

I encountered the same issue. Did you finally find out the reason? In my case the, even the vlan is missing, the communication is OK.

interface port-channel100
switchport
switchport mode trunk
switchport trunk native vlan 999
switchport trunk allowed vlan 100,106,140
vpc 100

Port Vlans in spanning tree forwarding state and not pruned
--------------------------------------------------------------------------------
Eth1/19 none
Eth1/20 192
Eth1/21 none
Eth1/22 100-102,106,108,115,140-141
Eth1/23 100-102,106,108,115,140-141
Eth1/24 100-102,106,108,115,140-141
Eth1/25 none
Po1 100-102,106,108,115,140-141
Po2 192
Po3 100-102,106,108,115,140-141
Po100 none

Thanks.

-Frank

[michaelbs]

Hi Frank,

no I still haven't found the reason yet but I haven't looked any further tbh.

Best Regards,
Michael

[BenBen]

Hi Michael,

Thank you for replying back. I rebooted the Nexus VDC, now the vlans showing up as "Vlans in spanning tree forwarding state and not pruned". I didn't open TAC case since I have other things to do at this moment.

Thanks.