Spanning Tree Root Bridge?

Hi jimbennin,

The Spanning tree root bridge will have all of its ports in a designated state, so traffic is allowed on all of them. Spanning tree doesn’t detect loops, it prevents them by putting redundant links into a discarding state so only a single link is used at a time. There shouldn’t be a loop created from a switch to an upstream provider because unless you have dual WANs to the same provider there won’t be a loop between the devices to even have a situation where spanning tree would be needed. Also there are probably routers between the networks and those would not pass broadcasts between the networks and prevent loops that way.

The provider/provided circuits are pure fiber fed Layer 2 connections.  When we initially set the first 2 sites up,  you could literally configure 2 laptops within the same /24 subnet and ping one another without and hops/routes etc...  That being said,  I think i'm understanding my issue more now since talking thru this a bit more.  

With the above in mind,  we have 2 sites with 2 separately served provider layer 2 circuits.  All traffic is provider vlan segregated thru the network.  The providers ethernet node has 4 ethernet drops.  I think where the issue resides is at (2) of the sites,  I've established (2) physical connections from each switch at each site to utilize the 2 seperate services from the provider.  I'm basically presenting the same MAC ID twice at each location.  Everything is fine until I plug in the 4th connection in which one of the 2 switches goes into blocking mode.  The spanning tree root is one of the 2 switches and it continues to function fine.  So in summary,  we have 4 ports, with RSTP enabled on all ports in a designated state.  I think i'm creating the Spanning tree loop in this case.  Hope this isn't too confusing...a diagram would do justice.  

OK...this is clearly a spanning tree issue and I'm wondering if anyone has reccomendations of port configurations for provider facing / Layer 2 networks...specifically pertaining to Spanning Tree setup.  Here is a snapshot of one of my WAN facing switchports.

Port 1/g24   Enabled

State: Forwarding                                Role: Root

Port id: 128.24                                  Port Cost: 20000

Port Fast:  No (Configured: no )                 Root Protection: No

Designated bridge Priority: 32768                Address: 5C:26:0A:F8:25:3B

Designated port id: 128.24                       External path cost: 20000

CST Regional Root: 70:00:5C:26:0A:F8:25:3B       CST Port Cost: 0

BPDU: sent 15, received 31587

Any thoughts/changes?  Any recommendations on utilizing a BPDU filtering mechanism to minimize the WAN traffic for spanning tree changes.