Configuring Rapid Transition
179
Figure 51 and Figure 52 illustrate the rapid transition mechanisms on designated
ports in RSTP and MSTP.
Figure 51
The RSTP rapid transition mechanism
Figure 52
The MSTP rapid transition mechanism
The cooperation between MSTP and RSTP is limited in the process of rapid
transition. For example, when the upstream switch adopts RSTP, the downstream
switch adopts MSTP and the downstream switch does not support
RSTP-compatible mode, the root port on the downstream switch receives no
agreement packet from the upstream switch and thus sends no agreement
packets to the upstream switch. As a result, the designated port of the upstream
switch fails to transit rapidly and can only turn to the forwarding state after a
period twice the forward delay.
Some other manufacturers’ switches adopt proprietary spanning tree protocols
that are similar to RSTP in the way to implement rapid transition on designated
ports. When a switch of this kind operating as the upstream switch connects with
a 3Com series switch running MSTP, the upstream designated port fails to change
its state rapidly.
The rapid transition feature is developed to resolve this problem. When a 3Com
series switch running MSTP is connected in the upstream direction to another
Summary of Contents for Switch 4210 9-Port
Page 22: ...20 CHAPTER 1 CLI CONFIGURATION ...
Page 74: ...72 CHAPTER 3 CONFIGURATION FILE MANAGEMENT ...
Page 84: ...82 CHAPTER 5 VLAN CONFIGURATION ...
Page 96: ...94 CHAPTER 8 IP PERFORMANCE CONFIGURATION ...
Page 108: ...106 CHAPTER 9 PORT BASIC CONFIGURATION ...
Page 122: ...120 CHAPTER 11 PORT ISOLATION CONFIGURATION ...
Page 140: ...138 CHAPTER 13 MAC ADDRESS TABLE MANAGEMENT ...
Page 234: ...232 CHAPTER 17 802 1X CONFIGURATION ...
Page 246: ...244 CHAPTER 20 AAA OVERVIEW ...
Page 270: ...268 CHAPTER 21 AAA CONFIGURATION ...
Page 292: ...290 CHAPTER 26 DHCP BOOTP CLIENT CONFIGURATION ...
Page 318: ...316 CHAPTER 29 MIRRORING CONFIGURATION ...
Page 340: ...338 CHAPTER 30 CLUSTER ...
Page 362: ...360 CHAPTER 33 SNMP CONFIGURATION ...
Page 368: ...366 CHAPTER 34 RMON CONFIGURATION ...
Page 450: ...448 CHAPTER 39 TFTP CONFIGURATION ...
Page 451: ......
Page 452: ...450 CHAPTER 39 TFTP CONFIGURATION ...
Page 470: ...468 CHAPTER 40 INFORMATION CENTER ...
Page 496: ...494 CHAPTER 44 DEVICE MANAGEMENT ...