Help with Multiple Switches interconnected to each other and back to a core switch (Spanning Tree)

[DoBoY]

I have a scenario that I am trying to figure out. I have multiple HP 5412Zl Switches. Here's the issue

I would like to knwo how this scenario would play out. 

3 Switches all interconencted by lag trunks, and also indivisually conencted back to a core switch. as seen in attached pic.

I'm wondering how this woudl work in regards to STP? would it block off all trunks back to core switch except for one? I have been tasked with trying to make the switches as resundant as possible but am limited in amount of Trunks i can have going to each switch. I only have 1 fiber uplink to each switch. it woudl be much easier if i could stack the switches but it seems that its not an option with the 5400 series + the fact that the HP stacking is not "true" stacking it seems.

Can anyone shed some light on this scenario or have any suggestions?

Thanks

[Richard Brodie_1]

If the core switch is root, then most likely you would have just the green links up. You could play around with the link costs to vary this.

If you are starting with multiple 5412s, then you ought at least to take a look at the 'meshing'  feature. It's not as full featured as the Comware IRF stacking but at first glance seems to fit your requirements. See the Advanced Traffic Management Guide.

[Vince_Whirlwind]

Hook it all up as per your diagram.

Reduce the spanning-tree value on the "core" to, say, "1" (or "4096").

Now, all your green links will come up. Each of your red links will be STP-blocked at one end.

If a green link fails, then one of the two red links to that switch will come live.