OS6900 Root Takeover

Hi just want to inquire if other is experiencing a Root Bridge Takeover on OS6900?

We have a deployment that has

spantree vlan 1900 admin-state enable spantree vlan 1900 priority 0

but the root bridge is being takeover by the same OUI of alcatel, but we could not find that mac on "show mac-learning mac-address"

Just wondering if others are encountering this.


OS6900 Version 8.6.203.R02

Did not face this issue but below command can help you to isolate from which port you are receiving the BPDU.

debug show spantree vlan 1900 ports


I recalled, did see such an issue in May 2019.

Logical setup.

ALE Switches(VC x2) CORE ------ OLT--------ONT(SFP)—ALE EDGE SWITCH(two uplinks one blocked using STP)

ALE Core switch STP Priority for all VLANs is 0.

OLT does not participate in STP.

BPDU sent out of Core switch is not corrupted until it reaches ONT. But When ONT egress the BPDU or goes out of ONT to EDGE SWITCH the BPDU is corrupted due to Memory issues on ONT.

ONT Modified the root bridge ID and send out the BPDU to Edge switch due to Memory issues.

This is very rare appears once or twice in a day only.

Nokia ONT was used and a software fix was provided.

We need to upgrade ONT’s and do a scan on ONT so that ONT will detect corrupted Memory and will not Memory for future