[c-nsp] ASR9K: BPDU stats on non-MSTP enabled interfaces

Pavel Stefanov p.stefanov at v6horizons.net
Fri Apr 11 09:21:52 EDT 2014


Hi all,

I need to enable MSTP with BPDU guard on several hundred ports on an 
ASR9K. Unfortunately, due to the high number of ports it is not feasible 
to identify whether the remote end runs xSTP and since MSTP is not 
enabled on the ports on the ASR9K, I cannot see the BPDU stats for 
themt. I tried looking in the STP trace but all I get is the below which 
gives no readable reference to the actual port number.

Is anyone aware of a command that can show whether BPDUs are actually 
being received and dropped on the port (due to the protocol not being 
enabled)?

RP/0/RSP0/CPU0:xxxx#show spanning-tree trace io | in configured

Fri Apr 11 12:26:12.911 UTC

Dec 12 17:18:08.819 l2protocols/ethernet/stp/io/unique 0/RSP0/CPU0 228# 
t1  080009e0/--: 0090 Packet   :- Received a BPDU on a port that does 
not have MSTP configured on it

Nov 26 12:29:04.138 l2protocols/ethernet/stp/io/fast 0/RSP0/CPU0 t1 
--------/--: 0010 Packet   :- Constructing BPDUs for 1 ports. 0 MSTIs 
configured, max 0 Rl2GP MSTIs.

I could potentially enable MSTP without BPDU guard first, check the 
stats and then enable BPDU guard on the port but that might cause a 
reconvergence event and drops for traffic on other ports so I have ruled 
this out as an option.

Thanks,
Pavel


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