LevelOne GTL-2691 - Manual (Page 245)

C HAPTER 8 | Spanning Tree Algorithm
Configuring Global Settings for STA
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Figure 100: Configuring Port Loopback Detection
C ONFIGURING G LOBAL S ETTINGS FOR STA
Use the Spanning Tree > STA (Configure Global - Configure) page to
configure global settings for the spanning tree that apply to the entire
switch.
CLI R EFERENCES
◆ "Spanning Tree Commands" on page 1061
C OMMAND U SAGE
◆ Spanning Tree Protocol 2
Uses RSTP for the internal state machine, but sends only 802.1D
BPDUs. This creates one spanning tree instance for the entire network.
If multiple VLANs are implemented on a network, the path between
specific VLAN members may be inadvertently disabled to prevent
network loops, thus isolating group members. When operating multiple
VLANs, we recommend selecting the MSTP option.
◆ Rapid Spanning Tree Protocol 2
RSTP supports connections to either STP or RSTP nodes by monitoring
the incoming protocol messages and dynamically adjusting the type of
protocol messages the RSTP node transmits, as described below:
■
STP Mode – If the switch receives an 802.1D BPDU (i.e., STP BPDU)
after a port’s migration delay timer expires, the switch assumes it is
connected to an 802.1D bridge and starts using only 802.1D
BPDUs.
■
RSTP Mode – If RSTP is using 802.1D BPDUs on a port and receives
an RSTP BPDU after the migration delay expires, RSTP restarts the
migration delay timer and begins using RSTP BPDUs on that port.
◆ Multiple Spanning Tree Protocol
2. STP and RSTP BPDUs are transmitted as untagged frames, and will cross any VLAN
boundaries.