Figure 8 Stp Before Max_Age Timer Expired - Zte ZXR10 5900 Series User Manual

Chapter 6 STP Configuration
packet and shut down the port which connects to switch D. This
solves the problem of network performance.
Loopback protection provides addtional layer 2 protection function.
Port Loopback
Protection
One reason for STP loop takes places in a network with redundant
Function
link is that one port which in blocking state becomes a designated
port and enters into FORWARDING state. A blocking port when
doesn't receive a BPDU packet. STP thinks that there isn't a loop.
Port will transmit from BLOCKING state to FORWARDING state,
this will create a loop.
When port loopback protection is configured and blocking port
don't receive BPDU packet. Port will transmit into LOOP_INCON-
SISTENT state. This state is blocking state and it doesn't transmit
any data.
F 8 STP B MAX_AGE T E
IGURE EFORE IMER XPIRED
In Figure 8, switch A is a root switch. There is link failure between
switch B and switch C which doesn't receive any BPDU packet from
switch B. Before MAX_AGE timer expired, port in switch C is still
in blocking state.
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