[c-nsp] Rapid-PVST and RSTP compatibility

[Steven Raymond]

On May 23, 2012, at 9:15 AM, Covalciuc Piotr wrote:

> We have a network built on CISCO switches with Rapid-PVST.
> Now, we want to integrate in the network the DELL PowerConnect
> switches, which supports RSTP only.
> 
> Does the Rapid-PVST compatible with RSTP?

From what I understand, the Ciscos will still run Rapid-PVST, not fall back to "RSTP".  Rapid-PVST will interwork with the Dells' RSTP, however.  On the cisco you can say "spanning-tree mode [ pvst | rapid-pvst | mst ]" without a "plain" RSTP option.  

PVST & R-PVST has limitations in the total number of vlans you can run, however, I think it is 128.

You may want to look at running MSTP, which should be somewhat less Cisco proprietary, and the dells will do MSTP as well.  MSTP then overcome the PVST vlan count limits.