rapid trees...

new roles

root port - each switch determines the lowest cost path to the root switch; that is its root port

designated - the lowest cost path to the root that is not the root port

alternate - the lowest cost path to the root that takes a different path to the root than the root port

backup - a redundant path to another segment that is already connected by a port

wow... take human bites...

what is the only switch in the tree that doesn't have a root port?
this is the root switch

is it ok to call it a switch now?

sw2950_01(config)#spann mode rapid-pvst

sw2950_01(config)#do sh spann vlan 50

VLAN0050
  Spanning tree enabled protocol rstp
  Root ID    Priority    24626
             Address     0009.b752.d780
             This bridge is the root (its really a switch)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    24626  (priority 24576 sys-id-ext 50)
             Address     0009.b752.d780
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Fa0/1            Desg FWD 19        128.1    P2p
Fa0/2            Desg FWD 19        128.2    P2p
Fa0/3            Desg FWD 19        128.3    P2p Peer(STP)
Fa0/4            Desg FWD 19        128.4    P2p Peer(STP)

what is 24576 plus 50