802.1w implementation clarification questions

[chris_storck]

I am playing around with a config with 50ish VLANs defined. I tried adding "spanning-tree 802-1w" command to each VLAN, but after 32 I get “error - start spanning tree on this vlan/vlan-group would exceed the maximum stp instance 32 limit”. If the switch can handle 254 instances of STP (according to Ruckus data sheet for ICX 7250) will it not handle the same number of instances of RSTP? Most of the documentation I find shows RSTP being configured per VLAN, but I did see where STP and RSTP can be a single tree. Is there a reason why I wouldn't run this as a single tree vs per VLAN? Now going down the single tree route I ran "spanning-tree single" then "spanning-tree single 802-1w". When I show the running config I see "spanning tree single" then all the VLANs defined followed by "spanning-tree single 802-1w". So is there one instance of STP running with RSTP enable for it or is this two separate instances? If I create any new VLANs it joins the rest of the VLANs before "spanning-tree single 802-1w".

[BenBeck · Accepted solution]

Hey Chris, 

Most people run 802.1w RSTP per-vlan. You are running into the default spanning tree instance maximum of 32. You can see more information in the 'show default value' command. You can change this with something such as:

conf t

system-max spanning-tree 128 (orother suitable number)

wr mem

*reload is needed for this to take effect

Once reloaded, you will be able to create your additional RSTP instances. Let me know if that works for you. 

[chris_storck]

Thank you

[morgan_denton1]

Hi There 

is there a way of managing this through the SmartZone Interface?

as I'm having a similar issue when using my switches through Smartzone.