Spanning Tree Issues

[Tuntz]

I have a problem with my network, over 70 switches connected to a WS-C4510R+E core router.  If a switch connects to my system, my entire network freezes up, for over 3 minutes.  I believe it is a spanning-tree problem.  My original installation was setup using pvst on the core and the first 10 switches or so.  After that point, switches added to my network were set up with rapid-pvst.  I have also found 1 small 8 port switch that does not have spanning tree set up at all.  These are all Cisco switches, mostly C2960X series, but some others as well.

It's simple enough to set all items to rapid-pvst, my fear however is that each time I change a switch, I will trigger another reset that will cause my network to go down again.  Any information would be greatly appreciated.

[Leo Laohoo]

Turn on BPDU Guard -- And watch people scream when they plugged their unmanaged switch stops working.

[MHM Cisco World]

this new SW, only config it priority in such that it never elect as new Root SW. 
and I think you will not face any issue.

you network is freeze because it enter to elect new root.

config root primary and secondary not protect your network from new low bridge-ID SW to elect as root, 
modify the new SW priority is better. 

[Joseph W. Doherty]

Possibly the best approach is to schedule maintenance where STP convergence, has no production impact.

During the maintenance, you'll want all your switches to run rapid-PVST.

You'll also want STP root switch (for each VLAN), generally, to be the physical L2 root (for each VLAN).  (You also should consider configurating a secondary root.)

There's possibly much more you could do to optimize your L2 STP topology, but insufficient information (starting with your number of VLANs and their "footprint" across your physical topology, whether you need a unique STP topology for every VLAN, etc.) to make good suggestions.

[Tuntz]

What I typically have is 2 VLANs per 48 port switch, in total nearly 200 VLANs.  This is surveillance network, most of the components connected are cameras.  Almost all switches or switch stacks are connected directly to the core, however there are instances of switches connected to other switches (trunk ports) due to cabling issues.  I also have 10 NVT switches connected via trunk ports.  Those all run using rapid-pvst, and each of those switches have their own vlan.

The only root bridge I have configured is my core router.