[j-nsp] Blocking BPDU´s in access interfaces (MX960)

[Matías Di Blasi]

Hi!

I need to block BPDUs on an access interfaces in a MX960, this 
interfaces don´t participates in spanning-tree (MSTP).

I need this because if a BPDU is received on an access interface 
(untagged), it is forwarded through a bridged domain that have some 
interfaces in trunk mode, and when Cisco Routers (76xx) receive a tagged 
BPDU, they switch to per-vlan STP, so i need avoid this behavior.

Can i do this by configuring BPDU-block on access interface?

The manual say "To configure the interfaces on which the system should 
not expect to receive BPDUs,
include the interfaces interface-name statement at the [edit protocols 
layer2-control
bpdu-block] hierarchy level. You can apply this statement to aggregated 
Ethernet
interfaces. By default, the system accepts all BPDUs received on any 
interface unless
you include this statement. If you configure this statement on a blocked 
interface,
and a BPDU is received on the interface, the system will disable the 
interface and
stop forwarding frames out the interface until the bridging process is 
restarted. You
can alter this behavior with the disable-timeout statement."

In which case you should configure BPDU-block on an interface that could 
be blocked by MSTP?  If an interface is blocked by MSTP, so it is 
receiving BPDUs, so always will be disabled if BPDU-block is configured, 
is this correct?

When an access interface with BPDU-block (not participating in MSTP) 
receives a BPDU, it is disabled? or the router just ignores the BPDU?

Thanks in advance,

Matías Di Blasi