BPDU protection

EX-series switches provide Layer 2 loop prevention through Spanning Tree Protocol (STP), Rapid Spanning Tree protocol (RSTP), and Multiple Spanning Tree Protocol (MSTP). Configure BPDU protection on interfaces to prevent them from receiving BPDUs that could result in STP misconfigurations, which could lead to network outages.

Enable BPDU protection on switch interfaces connected to user devices or on interfaces on which no BPDUs are expected, such as edge ports. If a BPDU is received on a BPDU-protected interface, the interface is disabled and stops forwarding frames.

Configure BPDU protection, use below CLI:

set protocols rstp interface ge-0/0/5 edge
set protocols rstp interface ge-0/0/6 edge
set protocols rstp bpdu-block-on-edge

Use below cli to check edge bpdu protoction is configured correctly:

ser@switch> show spanning-tree interface

Spanning tree interface parameters for instance 0

Interface Port ID Designated Designated Port State Role
port ID bridge ID Cost
ge-0/0/2.0 128:515 128:515 32768.0019e2503f00 20000 BLK DIS
ge-0/0/3.0 128:516 128:516 32768.0019e2503f00 20000 FWD DESG
ge-0/0/4.0 128:517 128:517 32768.0019e2503f00 20000 FWD DESG
ge-0/0/5.0 128:518 128:518 32768.0019e2503f00 20000 BLK DIS (Bpdu—Incon) <<<<<<<
ge-0/0/6.0 128:519 128:519 32768.0019e2503f00 20000 BLK DIS (Bpdu—Incon) <<<<<<<
ge-0/0/7.0 128:520 128:1 16384.00aabbcc0348 20000 FWD ROOT
ge-0/0/8.0 128:521 128:521 32768.0019e2503f00 20000 FWD DESG

When BPDUs arereceived from interface ge-0/0/5.0 and interface ge-0/0/6.0 the output from the operational mode command show spanning-tree interface shows that the interfaces have transitioned to a BPDU inconsistent state. The BPDU inconsistent state makes the interfaces block and prevents them from forwarding traffic.

Disabling the BPDU protection configuration on an interface does not unblock the interface. If the disable-timeout statement has been included in the BPDU configuration, the interface automatically returns to service after the timer expires. Otherwise, use the operational mode command clear ethernet-switching bpdu-error to unblock the interface.