I have a topology in which there is a main ring and some nodes in the main ring have a minor ring.
1- which STP configuration has the fastest convergence time? How would you configure spanning tree for all switches?
I think RSTP does the best, but Is there any other configuration to help convergence time?
2 – Does RSTP have any limitation? limitation In number of switches for instance? or incompatibility with other vendor's RSTP or spanning tree algorithm?
3- Is RSTP practical solution for this topology with a large number of switches? 45 switches as the main ring and more than 100 switches in minor rings?
4- Is there any other faster way, rather than spanning tree, to provide protection for this large network?
Thank you all!
Best Answer
Edit:
In case you've got multiple wires between closets you can still improve the topology significantly. Patching connections "through" = across intermediate enclosures allows you to reduce the tree depth significantly.
With just four links between closets (which is the absolute minimum we're deploying) you could e.g. elect Switch4 and Switch7(4) as "core" switches for separate L3 domains (you'll need L3 switches though). Make them redundant (stack) and connect all ring switches to the nearest stack. Run double L2 links between the domains and your network has significant improvements - it'll run xSTP without (too much) tweaking, has very few single point of failures, and increased throughput (depending on the exact details).
Make sure you run MSTP in (at least) two instances and configure the "core" switches as root bridges.