Shoot me now. I wish I could leave it at that, but I need to understand this piece of **** protocol. Please may you help?
I understand spanning-tree within a region, but I don't get it between regions (at least I think thats what i don't understand). So say you have this topology = http://gyazo.com/79199874aeeb2a00dbcaeb85477866ce
Region 3 has three MSTI's (msti 1 msti2 and msti0). Now region one and region two are running just MSTI0. So there is a total of 3 MSTI instances in total right?
So how can it be possible you have 4 root bridges?
-MSTI0 has a root bridge
-MSTI1 has a root bridge
-MSTI2 has a root bridge
-Each Region has a root bridge
How can there be a root bridge per region when there is no explicit MSTI running for it? Its just a non-MSTI spanning-tree instance that runs only within the region right? So I dont get it. MST has only 3 instances, but there are 4 spanning-tree instances running. Makes no sense what so ever in my eyes. I hate MST
To be honest I could also do with someone confirming if my MSTI0 is a possible path? Does it actually run through other regions? What happens if Sw2 becomes the regional root bridge; it's not connected to another region so the possibility that it can even become a regional bridge is beyond me?