Description

This article provides information on how to prevent unintended BPDU from other devices, without blocking the port.

Symptoms

If the EX device, which does not have any enabled spanning tree protocol, receives a BPDU packet, BPDU will be flooded to the same segment. This may cause unnecessary traffic and unintended spanning tree topology.

If unintended STP BPDU coming in on the EX device is noticed, you can disable the spanning tree protocol on the interface. The following configuration is the sample configuration to disable spanning tree protocol on ge-0/0/0.0 : 

set protocols stp interface ge-0/0/0.0 disable

It will prevent the STP BPDU from the peer device on ge-0/0/0 and also never transmits such STP BPDU to the peer device. However, other BPDUs from RSTP, MSTP, or VSTP enabled device, will not be prevented by the above configuration.

Solution

BPDU protection supports the drop mode from 12.2R1 and it will be useful to achieve it. The following sample configuration will prevent all of the BPDUs from the peer device on ge-0/0/0.0 , without blocking the port: 

set ethernet-switching-options bpdu-block interface ge-0/0/0.0 drop
For more information, refer to the following link: BPDU Protection for Spanning-Tree Protocols .

 

Modification History

2020-06-15: Article reviewed for accuracy; no changes required, article valid

 

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