Received SSTP BPDU with bad TLV on Nexus 7000

[Miroslav Miko]

Hi all,

I obtain this message on Nexus 7000:

2011 Dec 22 03:37:53 NNN %STP-2-RECV_BAD_TLV: Received SSTP BPDU

with bad TLV on port-channel1 VLAN0020

and following with err-disabled port

So, anybody, do you have some experiences on Nexus with this problem (e.g. NX-OS 5.1.5)?

I found some hints in discussion

https://supportforums.cisco.com/docs/DOC-5441

https://supportforums.cisco.com/message/962560#962560

but I think it not same problem that I received (I verified config).

thanks

[Peter Paluch]

Hello Miroslav,

Nice to meet you here!

Regarding the error you are experiencing: the first thing I would personally start searching for is whether there is a native VLAN mismatch or a cabling fault where some other VLAN leaks into the VLAN 20.

The message is somewhat cryptic: it tells you that the switch received a Cisco PVST or RPVST BPDU (which is addressed and encapsulated differently than IEEE STP/RSTP BDPUs) but this BPDU was missing a Cisco proprietary field that describes the VLAN ID in which the BPDU was originated. Not quite sure how this may have happened because PVST and RPVST BPDUs should always carry this field, and IEEE STP/RSTP BPDUs that do not have it would never get encapsulated, addressed and processed like PVST/RPVST BPDUs. Still, checking for native VLAN mismatches or inadvertent inter-VLAN interconnections is the first thing to do in these cases.

Best regards,

Peter

[Miroslav Miko]

Hi Peter,

I veried config and outputs on both sides affected ports. Configuration of trunks seems to be ok. Firts port of Nexus is directly connected  to other N7k and second interface (sorry, this log messages was discovered on two interfacess) is connected to Cat 65k.

I will check inter-Vlan interconnections. I separately opened TAC, but I'm very interested in this problem by reason of the  other case.

Thank you for answer.

Regards

Miro

[Peter Paluch]

Hi Miro,

It is possible that the offending BPDU was generated by a faulty IOS and that there is nothing wrong either with your configuration or with your physical cabling. Still, checking for configuration mistakes, native VLAN mismatches and inadvertent interconnection of ports in different VLANs is the first step in solving this issue, and I expect the TAC to request the same.

I did not quite understand your topology description. Do you believe you could upload an exact topology diagram depicting the interconnected switches and their links?

Best regards,

Peter