Spanning Tree
STP Status and Global Settings
Cisco 350XG & 550XG Series 10G Stackable Managed Switches
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The device supports the following Spanning Tree Protocol versions:
•
Classic STP – Provides a single path between any two end stations,
avoiding and eliminating loops.
•
Rapid STP (RSTP) – Detects network topologies to provide faster
convergence of the spanning tree. This is most effective when the network
topology is naturally tree-structured, and therefore faster convergence
might be possible. RSTP is enabled by default.
•
Multiple STP (MSTP) – MSTP is based on RSTP. It detects Layer 2 loops,
and attempts to mitigate them by preventing the involved port from
transmitting traffic. Since loops exist on a per-Layer 2-domain basis, a
situation can occur when a port is blocked to eliminate a STP loop. Traffic
will be forwarded to the port that is not blocked, and no traffic will be
forwarded to the port that is blocked. This is not an efficient usage of
bandwidth as the blocked port will always be unused.
•
MSTP solves this problem by enabling several STP instances, so that it is
possible to detect and mitigate loops separately in each instance. This
enables a port to be blocked for one or more STP instances but non
blocked for other STP instances. If different VLANs are associated with
different STP instances, then their traffic will be relayed based on the STP
port state of their associated MST instances. Better bandwidth utilization
results.
STP Status and Global Settings
The STP Status and Global Settings page contains parameters for enabling STP,
RSTP, or MSTP.
Use the STP Interface Settings page, RSTP Interface Settings page, and MSTP
Properties page to configure each mode, respectively.
To set the STP status and global settings:
STEP 1
Click
Spanning Tree
>
STP Status & Global Settings
.
STEP 2
Enter the parameters.
Global Settings:
•
Spanning Tree State
—Select to enable on the device.
•
STP Loopback Guard
—Select to enable Loopback Guard on the device.
