Fig. 8.16 Convergence Of 802.1D Network; Fig. 8.17 Network Convergence Of 802.1W (1) - Siemens S223 User Manual

User Manual
SURPASS hiD 6615 S223/S323 R1.5
A50010-Y3-C150-2-7619
1. New link created
Switch A
Switch B
BPDU Flow
Convergence of 802.1d Network
Fig. 8.16
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.
1. New link created
Switch A
Switch B
Network Convergence of 802.1w (1)
Fig. 8.17
ROOT
2. Transmit BPDU
at listening state
Switch C
3. Block to
prevent loop
Switch D
ROOT
2. Negotiate between
Switch A and ROOT
(Traffic Blocking)
Switch C
Switch D
UMN:CLI
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