[c-nsp] VSS fast-hello link

[selamat pagi]

Would like to verify the physical fast-hello setup of my VSS-cluster
(with SW1 and SW2):

  SW1   ---    Vlan z        ---   SW4
    ¦                                         ¦
Vlan z                                 Vlan z
    ¦                                         ¦
SW1   ---     VSL link        ---   SW2
          ---     VSL link        ---

I am aware that fast-hello on SW1 and SW2 needs to be a dedicated port.

But need these 2 dedicated ports be connected physically back-to-back OR
can I span it with a vlan accros other switches ?

many thanks,
 keti