stp on GbE2 Interconnect blade switch (nortel)

[Alexander Leutz]

hi!

I have an problem with the Spanning Tree Protocol on the GbE2 Interconnect blade switch.
We use the internal trunk over ports 17, 18.
But there online one uplink for the whole blade enclosure. We want a reduntant connection with 1 uplink each blade switch, thought we enabled stp on the blade switches and our core switch. but when we active 2 uplinks, the core switch gets in trouble and neither the core nor the blade switches blocked the second uplink.
why?
anybody out there having the same scenario working correctly?

greats, alexander.

[Anders_35]

If your spanning-tree is correctly configured this should not be a problem. Default settings should be good enough, except the bridge priority, which usually should be a lower number for the Nortel than the GbE2's.
We run our blade enclosures through a Nortel 8xxx-something without problems.

How have you configured your switches?

If the Nortel is root, or closer to root, the GbE2's will block the interconnect trunk on ports 17 and 18, since the upload ports give shorter paths to root.

If you want to force the interconnect link open, you must do so by changing the path costs, not by turning spanning-tree off on those ports (if that is even possible, I don't know).