Inconsistent peer vlan c9500 issue

[bshoja]

Hello Folks,

I have one question that I need help!

Core Sw ---> Access Sw
Native vlan is the same on both side.
One I create a vlan on the core sw everything is okay, but once I do ont the access for every vlan I have below output on the core.

using PVST!!

%SPANTREE-2-BLOCK_PVID_PEER: Blocking Port-channel2 on VLAN0155. Inconsistent peer vlan.
%SPANTREE-2-BLOCK_PVID_LOCAL: Blocking Port-channel2 on VLAN33. Inconsistent local vlan.
%SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking Port-channel2 on VLAN0155. Port consistency restored.
%SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking Port-channel2 on VLAN33. Port consistency restored.

Now I am concerned if it is a normal behaviour or......?

Best Regards,

bshoja

[Torbjørn]

Could you post port and spanning-tree configurations from the core and one access switch? I suspect that this might be related to DTP negotiating between access-port and trunk. Also, are you running VTP in your network?

[bshoja]

Hi Torbjørn,

Thank you for your reply. no VTP configured

below is spanning tree config:

spanning-tree mode rapid-pvst
spanning-tree extend system-id
spanning-tree vlan 1-4093 priority 4096

!
interface Port-channel2
switchport trunk native vlan 155
switchport mode trunk

same config on access just STP priority is different of course!

BR,
bshoja

[MHM Cisco World]

It normal behave dont worry 
https://www.cisco.com/c/en/us/support/docs/lan-switching/spanning-tree-protocol/24063-pvid-inconsistency-24063.html

when you add VLAN to both SW the PVST unblokcing the port-channel and pass traffic normally 
MHM

[bshoja]

Thanks @MHM Cisco World, but i am worried about the native vlan. why it is going to Inconsistent state?

[MHM Cisco World]

Are native vlan is vlan1 or other vlan ??

If it other vlan then it same as any vlan if it vlan1 then there is issue since vlan1 is by defualt in any SW and can not delete.

MHM

[balaji.bandi]

Do you have both the VLAN created on both the switches ?

You have setup both the side same Native VLAN ?

as per the message you need to setup one of the switch as root bridge - check show span summary give you where the root bridge.

other hand, what IOS XE code running on both the switches ?

for inconsistency troubleshooting :

https://www.cisco.com/c/en/us/support/docs/lan-switching/spanning-tree-protocol/24063-pvid-inconsistency-24063.html

does the spanning tree config on both switches same ? (only one should have Lower priority other one should be default)

[bshoja · Accepted solution]

hi all,

Thank you for your advices. 
By definition, these error messages are shown when vlan tag does not match the VLAN ID inside the spanning-tree BPDU. . The behavior was addressed under several different software defects which has been confirmed as cosmetic/informative.
bugs CSCvh80678, CSCvh68048, CSCwf57411 and CSCvd49393

SW-A could have got a software event that required to reprogram the hardware setting for the port connecting to SW-B. There is small time difference between when the software event happens and when the hardware gets programmed. This time difference (or a race condition) can result in a BPDU from SW-A to SW-B that is inconsistent.

• The STP protocol recovers by itself, and no user intervention is needed.
  

BR

bshoja

[MHM Cisco World]

• The STP protocol recovers by itself, and no user intervention is needed.

As I mentioned before Dont worry it temporarily not permanently issue. 

Thanks to share bugs number it help me

Have a nice day 

MHM