RSTP Blocking Port

[Pieter 't Hart]

I repeat again
>>>
CST Root Path Cost : 2000
CST Root Port : 1
<<<
this shows the CST root IS connected through port-1 of this switch.


>>>
Port Type | Cost rity State | Bridge Time PtP Edge
----- --------- + --------- ----- ---------- + ------------- ----- --- ----
A1 10GbE-SR | 2000 128 Forwarding | 0012f2-3f3b00 2 Yes No
<<<

As the costs between paths "port-1" and A1 are both 2000 there is no direct reason to select A1 over port-1.

carefully check all devices (switches) connected through port-1 (with "show mac-address 0012f2-3f3b00" ) where the loop back to the Rx16 comes from.

[Pieter 't Hart]

beware, many switches that doesn't run any spanning-tree protocol itself DO forward BPDU packets from other switches they recieve.

And just because your HP-switch don't run spanning-tree, it won't add to the hop-count.
I'm not sure how it will handle costs, by bandwidth.

Maybe if you DO enable spanning-tree on this switch, you can easier isolate the fault .

Pieter