[c-nsp] MST x RAPID-PVST interoperability issue

[Velimir Filipov]

Hello,

As far as I know, you must have the same native vlan id on both sides.

It's like that even if both switches were running same type of STP.

When you have an interface working in trunk mode, when using PVST (not sure for MST), the switch would put the VLAN id in the BPDUs that it transmits, even on the Native untagged vlan. 

Unless you manage to have VLANs 29 and 120 use the same tag on both sides, all you can do is filter the BPDUs on that link (spanning-tree bpdufilter enable), but that would separate the STP domain, which should be ok if you don't have redundant links.

Best regards.


Wednesday, February 5, 2014, 1:19:59 PM, you wrote:

> Hi,

> I'm trying to deploy working STP enviroment where one side runs MST and
> the other runs rapid-pvst, with diffent native vlans on both sides.

> Scenario is quite complex, but I've stucked at the very beginning.

> I need to carry two VLAN's over one single link, 728 being tagged.

> Side A (7606 with RSP720)

> STP mode rapid-pvst
> Vlans 29,728

> Interface configuration ->

> interface TenGigabitEthernet1/1
> В  description LINK-CUST
> В  switchport
> В  switchport trunk encapsulation dotq1
> В  switchport mode trunk
> В  switchport trunk allowed vlan 29,728
> В  switchport trunk native vlan 29
> В  switchport nonegotiate
> В  load-interval 30



> Side B (4948E)

> STP mode MST
> Vlans 120,728

MST config ->>

> instance 2 vlan 120
> instance 4 vlan 728


> Interface configuration ->

> interface TenGigabitEthernet1/50
> В  description Uplink-primary
> В  switchport
> В  switchport trunk native vlan 120
> В  switchport trunk allowed vlan 120,728
> В  switchport mode trunk
> В  switchport nonegotiate


log from side B ->>

> %SPANTREE-2-RECV_PVID_ERR: Received BPDU with inconsistent peer vlan id
> 29 on TenGigabitEthernet1/50 VLAN120.
> %SPANTREE-2-BLOCK_PVID_LOCAL: Blocking TenGigabitEthernet1/50 on MST0.
> Inconsistent local vlan.
> %SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking TenGigabitEthernet1/50 on
> MST0. Port consistency restored.
> %SPANTREE-2-RECV_PVID_ERR: Received BPDU with inconsistent peer vlan id
> 29 on TenGigabitEthernet1/50 VLAN120.
> %SPANTREE-2-BLOCK_PVID_LOCAL: Blocking TenGigabitEthernet1/50 on MST0.
> Inconsistent local vlan.


> C4948E-prgx#show spanning-tree interface Te1/50

> Mst Instance В  В  В  В Role Sts Cost В  В  В Prio.Nbr Type
> ------------------- ---- --- --------- -------- 
> --------------------------------
> MST0 В  В  В  В  В  В  В  В Desg BKN*2000 В  В  В 128.50 В  P2p Bound(PVST) *PVID_Inc
> MST2 В  В  В  В  В  В  В  В Desg BLK 2000 В  В  В 128.50 В  P2p Bound(PVST)
> MST4 В  В  В  В  В  В  В  В Desg BLK 2000 В  В  В 128.50 В  P2p Bound(PVST)





> Can this be done (different native vlans) between PVST and MST enabled
> switches?



> Thank you!



> Jiri Prochazka

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