We ran into a problem the other day when a member of our staff inadvertently doubly connected in a cheap switch (no STP) into another switch that had STP disabled. (The second switch was connected to our main network.) The resulting packet storm brought down our network.
If our simplified network topology looks something like this
.--. |S1| '--' | .--. ___ .--. |S2| ___ |S3| '--' '--'
(Sorry for the crude ascii art, I'm trying to illustrate that S2 and S3 are connected twice, creating a bridging loop)
- S1 is actually a rack of Cisco switches
- S2 is a Netgear smart switch with STP disabled
- S3 is an embedded switch with no STP
This area isn't my forte, so I'm not even sure if this is possible, but if our network looks something like this, is there a way to protect S1 from the ensuing broadcast storm between S2/S3?
Update with a little more info:
- Rack-mounted Cisco switches are a mix of SG200-50's, -26's, and -18's
- Netgear is a GS108Tv2 running firmware v188.8.131.52
- The more esoteric piece of equipment is a small embedded switch that goes in an industrial controller, link is here: https://www.phoenixcontact.com/online/portal/us?uri=pxc-oc-itemdetail:pid=2891001&library=usen&pcck=P-08-08-10-06-01&tab=2. The PDF (downloads tab) indicates something about a "multi-address function" but I don't think this is STP/RSTP.
Thanks for all the answers so far. I really appreciate it.