Folks: I'm trying to understand importance of having a "high end" switch as the root switch. I see references of it here and there but haven't seen a solid document on it. I've spent quite some time googling spanning tree and root switches. I accidently ran into a situation where a low end "access" switch became the root and things still seem to be working and I'm trying to understand why and what the downsides are. Here is a little backgroud:
I have a fairly simple network, with a potential for growth and hence the need for proper STP configuratoin. I'm trying to understand the worse case scenario for a misconfigured "root" switch. I understand that I can force the root switch to be the core switch by changing the priority and also understand the use root gaurd protection and other techniques.
Here is what my network looks like:
Switch (M) Core switch and also desired STP root, VLAN 20,30,40 ) / | \\ switch A(VLAN 20) switchB (VLAN 20) switch C (VLAN 30)
Now it turns out that becuase of lower MAC ID, switch A become my root for VLAN 20.
Here is what my STP diagram looks like for VLAN 20.
Switch A (root) DP | RP Switch M (Core) DP | RP Switch B Questions:
- Things seem to be working with switch A as the root switch. Where should I look for spanning tree misconfiguration/bottlenecks? Any IOS command recommendations?
- What is the worse case scenario with having switch A as the STP root?
- Does the bottleneck only happen when spanning tree reconverges or would it affect layer 3 traffic in any way?