Today, A tech at a remote server site unplugged a single port from one of our fiber converters for our WAN uplink from a Dell PowerConnect Switch. We lost all networking on the 3 stacked 48 port switches for a while, and looking at the log, it appears that removing that one port (which is on a seperate VLAN that only 3 of our ports use) Caused Spanning tree to go crazy.. Apparently, when we plugged the Fiber into the switch 2 days ago, the switch decided to make it the "root port" of the spanning tree config. Once the root port was unhooked, all ports look like they went into a blocking state for a while.
I am more of a server guy, and don't really understand Spanning tree. I thought I set them all to use Rapid STP, but they all went down for more than the few seconds RSTP should take. Is this the expected behavior of the "root port" in spanning tree being removed? Shouldn't the root port be on the vlan that most of the hosts use? (we use the 3 ports in the seperate vlan as a "DMZ" so our two clustered firewalls can both reach the WAN fiber. We have a similar 3 port VLAN setup for our backup internet connection to a cable modem)