Filter
Top Products
Spanning Tree
Configuring STP Status and Global Settings
Cisco Small Business SG200 Series 8-port Smart Switch 120
6
• STP Operation Mode—Select one of the following STP modes:
- Classic STP—Operates according to the original IEEE 802.1D spanning
tree protocol.
- Rapid STP—Is the default value and provides faster spanning tree
convergence after a topology change than does classic STP.
• BPDU Handling—Bridge Protocol Data Units (BPDUs) are the messages
exchanged between switches to calculate STP topology. Select the method
of BPDU packet handling when the spanning tree is disabled on an interface:
- Filtering—Enables the port to discard BPDUs received on interfaces that
are not enabled for STP.
- Flooding—Allows flooding of BPDUs received on non-spanning-tree
ports to all other non-spanning-tree ports.
STEP 2 Specify the following bridge setting:
• Priority—The bridge priority value. When switches or bridges are running
STP, each is assigned a priority. After exchanging BPDUs, the switch with the
lowest bridge identifier becomes the root bridge. The bridge priority must
be a multiple of 4096. If you specify a priority that is not a multiple of 4096,
the priority is automatically set to the next lowest multiple of 4096. For
example if you attempt to set the priority to any value between 0 and 4095,
it will be set to 0. The default priority is 32768. The valid range is 0-61440.
• CST Bridge Max Age—The amount of time in seconds that a bridge waits
before implementing a topological change. The valid range is 6-40 seconds.
The default is 20 seconds.
• CST Bridge Forward Delay—The amount of time in seconds that a bridge
remains in a listening and learning state before forwarding packets. The valid
range is 4-30 seconds. The default is 15 seconds.
The following information appears in this section of the page:
• Hello Time—The interval at which a bridge sends configuration messages.
• Max Hops—The number of hops before a BDPU is discarded and the port
information is aged out. The maximum hop count is set to 20 and is not
configurable.
• Hold Time—The minimum time period, in seconds, that elapses between
the transmission of Configuration BPDUs through a bridge port.