![background image](http://html1.mh-extra.com/html/3com/corebuilder-3500/corebuilder-3500_implementation-manual_440863130.webp)
130
C
HAPTER
7: B
RIDGE
-W
IDE
AND
B
RIDGE
P
ORT
P
ARAMETERS
Figure 24 illustrates the factors that cause a port to change from one
state to another. The arrows indicate the direction of movement between
states. The numbers correspond to the factors that affect the transition.
Figure 24
Factors in Spanning Tree Port State Transitions
As shown in Figure 24, for a port in the blocking state to transition to the
listening state, STP must select that port as a designated or root port.
After the port enters the listening state, forward delay must expire before
the port can transition to the learning state. Then another forward delay
period must expire (listening state) before the port can transition to the
forwarding state. If you disable a port in the listening, learning, or
forwarding state or if port initialization fails, then that port becomes
disabled.
Disabled
Blocking
Listening
Learning
Forwarding
Port enabled by either network administrator or initialization
Port disabled by either network administrator or failure
Spanning Tree algorithm selects port as designated or root
Spanning Tree algorithm does not select port as designated or root
Forwarding timer (forward delay) expires
and
1
2
1
2
3
4
5
5
1
5
2
3
4
Summary of Contents for CoreBuilder 3500
Page 44: ...44 CHAPTER 2 MANAGEMENT ACCESS ...
Page 58: ...58 CHAPTER 3 SYSTEM PARAMETERS ...
Page 86: ...86 CHAPTER 5 ETHERNET ...
Page 112: ...112 CHAPTER 6 FIBER DISTRIBUTED DATA INTERFACE FDDI ...
Page 208: ...208 CHAPTER 9 VIRTUAL LANS ...
Page 256: ...256 CHAPTER 10 PACKET FILTERING ...
Page 330: ...330 CHAPTER 12 VIRTUAL ROUTER REDUNDANCY PROTOCOL VRRP ...
Page 356: ...356 CHAPTER 13 IP MULTICAST ROUTING ...
Page 418: ...418 CHAPTER 14 OPEN SHORTEST PATH FIRST OSPF ...
Page 519: ...RSVP 519 Figure 94 Sample RSVP Configuration Source station End stations Routers ...
Page 566: ...566 CHAPTER 18 DEVICE MONITORING ...
Page 572: ...572 APPENDIX A TECHNICAL SUPPORT ...
Page 592: ...592 INDEX ...