[c-nsp] Cisco RSTP interop with 802.1w equipment

[Phil Mayers]

Marian Ďurkovič wrote:
> On Fri, Oct 16, 2009 at 12:06:39PM +0100, Phil Mayers wrote:
>>> Aren't Cisco switches supposed to send BPDUs also to IEEE STP MAC address
>> Generally, no. Vlan 1 is treated specially.
>>
>>> on 802.1Q trunks? Or is there any special config needed for this?
>> Vlan number 1 will interop, so if you do this:
>>
>> int Gi1/1
>>   switchport mode trunk
>>   switchport trunk native vlan 1
>>   switchport trunk allowed vlan 1,2,3
>>
>> ...then vlan 1 will form an 802.1w adjacency with the neighbour, vlans 2 
>> and 3 will just pass straight through it.
> 
> Is that ultimately limited to vlan #1, or could it be done with the native
> vlan on trunk (e.g. vlan #1520) as well?

vlan #1 as far as I know.

> 
> We're removing vlan #1 from all trunks by principle for obvious reasons...

Sure. It's not a very useful feature ;o)