Spanning Tree
STP Interface Settings
Cisco Sx350, SG350X, SG350XG, Sx550X & SG550XG Series Managed Switches, Firmware Release 2.2.5.x 226
12
• STP—Enables or disables STP on the port.
• Edge Port—Enables or disables Fast Link on the port. If Fast Link mode is enabled on
a port, the port is automatically set to Forwarding state when the port link is up. Fast
Link optimizes the STP protocol convergence. The options are:
- Enable—Enables Fast Link immediately.
- Auto—Enables Fast Link a few seconds after the interface becomes active. This
allows STP to resolve loops before enabling Fast Link.
- Disable—Disables Fast Link.
NOTE It is recommended to set the value to Auto so that the device sets the port to fast
link mode if a host is connected to it, or sets it as a regular STP port if connected to
another device. This helps avoid loops.
Edge Port is not operational in MSTP mode.
• Root Guard—Enables or disables Root Guard on the device. The Root Guard option
provides a way to enforce the root bridge placement in the network.
Root Guard ensures that the port on which this feature is enabled is the designated port.
Normally, all root bridge ports are designated ports, unless two or more ports of the
root bridge are connected. If the bridge receives superior BPDUs on a Root Guard-
enabled port, Root Guard moves this port to a root-inconsistent STP state. This root-
inconsistent state is effectively equal to a listening state. No traffic is forwarded across
this port. In this way, Root Guard enforces the position of the root bridge.
• BPDU Guard—Enables or disables the Bridge Protocol Data Unit (BPDU) Guard
feature on the port.
The BPDU Guard enables you to enforce the STP domain borders and keep the active
topology predictable. The devices behind the ports that have BPDU Guard enabled
cannot influence the STP topology. At the reception of BPDUs, the BPDU guard
operation disables the port that has BPDU configured. In this case, a BPDU message is
received, and an appropriate SNMP trap is generated.
• BPDU Handling—Select how BPDU packets are managed when STP is disabled on
the port or the device. BPDUs are used to transmit spanning tree information.
- Use Global Settings—Select to use the settings defined in the STP Status and Global
Settings page.
- Filtering—Filters BPDU packets when Spanning Tree is disabled on an interface.
- Flooding—Floods BPDU packets when Spanning Tree is disabled on an interface.
To Next Page
Loading...
