I want to know the relation between VLAN and STP protocol.Since STP is running over each port,how VLANs associated with this.Also I want to know the MIB which gives the data regarding STP for a particular VLAN.
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It depends, There are two primary forms of Spanning trees maintained across VLANs
Per-VLAN Spanning Tree (PVST) maintains a spanning tree topology for each VLAN, It uses ISL Trunking (as opposed to Dot11q) and allows a VLAN trunk to be forwarding for some VLANs while blocking for other VLANs. Since PVST treats each VLAN as a separate network, it has the ability to load balance traffic (at layer-2). Tragically, this is not compatible with Rapid Spanning Tree unless you specifically configure it as such with PVST+ or R-PVST.
MSTP isn't all so different, Aside from being open standard, and aside from using the Dot11Q standard rather than the proprietary Cisco ISL standard, the main (huge) advantage is that MSTP includes all of its spanning tree information in a single BPDU. Not only does this reduce the number of BPDUs required on a LAN to communicate spanning tree information for each VLAN, but it also ensures backward compatibility with RSTP (and Classic STP as well!). PVST is not so kind.
Theres alot of compelling reasons for setting up MSTP rather than PVST, even if it may be more difficult - Not nessasarily limited to having superior Creative skills with Spanning Tree Topologies, Deduction. Reason. Nodding intelligently. I’ve noticed that many experienced users of MSTP seem to be clear thinkers and objective about network design. (In contrast to: heavily biased and coarse :) . Beyond that, MSTP does everything PVST does - better. Load balancing is superior, unversal device support, etc. etc. You'll thank yourself later if you do MSTP.
As far as MIBs are concerned, Theres quite a few different MIBs and object identifiers across several different devices and components of Spanning Tree, You're probably looking for stpRoutingInfo.