Siemens S223, S323 user manual Network Convergence of 802.1w A50010-Y3-C150-2-7619 207

User Manual	UMN:CLI
SURPASS hiD 6615 S223/S323 R1.5

ROOT

1. New link created

Switch A

2. Transmit BPDU

at listening state

Switch B Switch C

3. Block to prevent loop

BPDU Flow

Switch D

Fig. 8.16 Convergence of 802.1d Network

This is very an epochal way of preventing a loop. The matter is that communication is disconnected during two times of BPDU Forward-delay till a port connected to switch D and SWITCH C is blocked. Then, right after the connection, it is possible to transmit BPDU although packet cannot be transmitted between switch A and root.

ROOT

1. New link created

Switch A

2. Negotiate between Switch A and ROOT (Traffic Blocking)

Switch B

Switch C

Switch D

Fig. 8.17 Network Convergence of 802.1w (1)

A50010-Y3-C150-2-7619 207