Spanning-Tree

[sfrgrove1]

Hello All

I was hoping someone would be able to help me with a spanning-tree question. I understand the need to use Spanning-tree but not sure about it's usage in my environment. We have one Nexus 7009 being used as our Core. I have 13 buildings and each of them have a ten Gig Fiber run back to the Nexus 7009. In each on my buildings I have a Cisco 2960 in the MDF and that is what the Fiber goes into. Hanging off the Cisco 2960 I have a few HP 2530 Switch using trunk ports. We don't have any kind of redundancy between any of our switches. I'm hoping for maybe some suggestions on what I should be configuring the Trunk ports and the Access ports. All routing is done back at the Nexus 7009 and not in any buildings. We have somewhere between 75-100 Vlans. Thanks for any help.

As a side note we are a public School District so that is the need for so many Vlans.

Rich G

[Mark Malone]

Just on your access ports its best practice to set them all to use stp portfast and bpduguard the reason being if there is an actual issue and something fails these are removed from the stp calculation and this reduces traffic flooding and resources on your network being used up during  that time reducing the stp calculation time and l2 convergence , regarding the redundant links first you should know what your stp root is , usually you select your core switch for this or a centrally located powerful switch in your topology and set the stp priority to be the lowest and then also a good idea to have a backup root switch in case that physically failed

spanning-tree root primary

spanning-tree root secondary

regarding redundant links always good to have a second path , 2 ways you could use portchannels bundle a few links together for extra throughput and resiliency or if setting backup paths you could set the stp cost of the link very high to something like 5000 so it only kicks in if primary path fails that has a lower cost

Its a good idea to know your layer 2 STP topology so when you have set it up you know exactly whats what so when something actually goes wrong you will have a good idea what to expect and what has happened as its an automatic feature based in what you configure but if you leave it to default sometimes in can be hard to find the reason after the fault what exactly went on

any questions just ask il do my best to answer ,my HP side is limited though in cli