Ruijie RG-S2900G-E Series, Configuration Manual

Page: 263 / 943

Configuration Guide MSTP Configuration
Caution
1. Incorrectly using ROOT Guard leads to network link
breakdown.
2. If you enable ROOT Guard on non-designated port, the
non-designated port will be enforced as designated port and
show BKN status(blocking status).
3. If MST0 enters BKN status because it receives configuration
message of higher priority on a port, ROOT Guard will enforce
the port in all the other instances to enter BKN status.
4. ROOT Guard or LOOP Guard takes effect at the same time.
That is , they can not both take effect at the same time .
5. The AutoEdge function is disabled when enabling the ROOT
Guard-enabled port.
Understanding LOOP Guard
Due to breakdown of one-way link, root port or backup port becomes
designated port, being ready to forward because they can not receive BPDU,
causing the loop in the network, which Loop Guard function can prevent.
For the ports configured loop guard, if they can not receive BPDU, the port
roles will be migrated. However, the port state is always set as discarding till
the port receive BPDU again and recalculate spanning tree.
Caution
You can enable LOOP Guard based on global or interface.
ROOT Guard or LOOP Guard takes effect at the same time.
That is , they can not both take effect at the same time .
The AutoEdge function on all interfaces is ineffective when
enabling LOOP Guard function globally.
The AutoEdge function on the interface is ineffective when
enabling LOOP Guard function in the interface configuration
mode.
Configuring MSTP
Default Spanning Tree Configuration
The following table lists the default configuration of the Spanning Tree protocol.
Item Default value
Enable State Disable
STP MODE MSTP