SPANNING TREE OVERVIEW
STP PROTECTION
BPDU FILTERING
DISABLES BPDUs ON PORT
REQIURES PORT-FAST
LOSS OF BPDUs
LOOP-GUARD
DETECTS LOSS OF BPDUs
WITHOUT: PORT STARTS FORWARDING
WITH: PORT BECOME INCONSISTENT
UDLD(UNI-DIRECTIONAL LINK DETECTION)
1 WAY OR DIRECTIONAL LINK DETECTION
DETECTS BY SENDING KEEPALIVES
SPEED CONVERGENCE
PORT-FAST
ON ACCESS LAYER CONNECTED TO HOSTS TO REMOVE MAX-AGE TIMER DELAY
UPLINK-FAST
FOR DIRECT FAILOVER
BACKBONE-FAST
FOR INDIRECT FAILOVER
TYPES OF STP
802.1D(TRADITIONAL)
PORT ROLES
ROOT
DESIGNATED
BLOCKING
PORT STATES
DISABLED
BLOCKED
LISTENING
LEARNING
FORWARDING
TIMERS
HELLO (2 sec)
FORWADING (15 sec)
MAX-AGE (20 sec)
COMMON SPANNING-TREE
1 INSTANCE OF STP
DOT1Q BASED (NATIVE VLAN)
PER-VLAN SPANNING-TREE
1 INSTANCE OF STP PER VLAN
ISL BASED
PER-VLAN SPANNING-TREE PLUS +
INTEROPERABILITY BETWEEN CST & PVST
OPERATES OVER BOTH DOT1Q AND ISL
RAPID SPANNING-TREE (802.1W)
PORT ROLES
ROOT
DESIGNATED
ALTERNATE
BACKUP
PORT STATES
DISCARDING
LEARNING
FORWARDING
PORT TYPES
EDGE PORT
HOST PORT
NO LONGER EDGE WHEN BPDUs RECIEVED
ROOT PORT
POINT TO POINT PORT
DESIGNATED PORT
HALF-DUPLEX ON SHARED MEDIA
RAPID PER-VLAN SPANNING-TREE(RPVST)
MULTIPLE SPANNING-TREE (802.1S)
1 INSTANCE OF STP FOR A GROUP OF VLANs
UPTO 15 INSTANCES SUPPORTED ON EVERY SWITCH