CCNA 2 - Capitulo 5.3

CCNA 2 - Capitulo 5.3

1. EVOLUTION OF STP

   • PVST - PER VLAN SPANNING TREE (PVST)
     • THERE IS A ROOT BRIDGE ELECTED
       • EACH SPANNING TREE INSTANCE
     • POSSIBLE HAVE DIFFERENT ROOT BRIDGES FOR DIFFERENT SETS OF VLANs
     • SUPPORT
       • PORTFAST
         • ONLY ACCESS PORT (END DEVICES))
         • MINIMIZE THE TIME THAT ACCESS PORTS MUST WAIT FOR SPANNING TREE TO CONVERGE
           • SWITCHPORT TRANSITIONS FROM IMMEDIATELY BLOCKING TO FORWARDING STATE
         • BPDUs SHOULD NEVER BE RECEIVED ON PORTFAST ENABLE SWITCH PORTS
         • SOLVES THE PROBLEM UNABLE TO GET IPV4 FROM DHCP SERVER
       • UPLINK FAST
       • BACKBONE FAST
       • BPDU GUARD AND FILTER
         • PUTS THE SWITH PORT IN AN ERRDISABLED
       • ROOT GUARD
       • LOOP GUARD
     • STP CONFIGURED TO OPERATE IN AN ENVIRIONMENT WITH MULTIPLE VLANs
     • ENHACNCEMENT OF STP
     • CISCO PROPRIETARY
   • RAPID SPANNING TREE PROTOCOL (IEEE 802.1W)
     • FASTER CONGERGANCE THAN STP
     • SAME STP ALGORITHM
     • PORT STATES
       • DISCARDING
         • INCORPORATE (DISABLE , BLOCKING & LISTENING - STP )
       • LEARNING
         • LEARN
           • MAC
         • PROSCESS
           • BPDU
       • FORWARDING
         • LEARN
           • MAC
         • PROCCESS
           • BPDU
     • PORT ROLES
       • ROOT PORT
       • DESIGNATED PORT
       • BACKUP PORT (RSTP)
         • BACKUP A SHARED MEDIUM
       • ALTERNATE PORT (RSTP)
         • ALTERNATE PATH TO THE ROOT BRIDGE
     • SUPERSEDES THE ORIGINAL 802.1D
   • RAPID PVST+
     • RSTP USER PVST+
     • CISCO PROPRIETARY
   • MST IEEE 802.1s
     • REDUCES THE NUMBER OF STP INSTANCES
     • CISCO PROPRIETARY
   • MULTIPLE SPANNING TREE PROTOCOL (MSTP)
     • MAPS MULTIPLE VLANS INTO THE SAME SPANNING TREE INSTANCE.
   • STP IEEE 802.1d
     • UPDATE VERSION STP , INCOPORATING 802.1W
     • IT ASSUMES ONE SPANNING TREE INSTANCE , REGARDLESS OF THE NUMBER OF THE VLANs

2. OTHERS MECHANISM LOOP PREVNTION ?

   • MULTIPLE SYSTEM LINK AGGREGATION (MLAG)
   • SHORTEST PATH BRIDGING (SPB)
   • TRANSPARENT INTERCONNECT OF LOTS OF LINK (TRILL)