E-Series Multi-Instance Spanning Tree And Vlans; Spanning Tree On A Circuit-By-Circuit Basis; E-Series Spanning Tree Parameters - Cisco ONS 15454 SDH Configuration Manual

E-Series Spanning Tree (IEEE 802.1D)
Multiple circuits with STP protection enabled will incur blocking if the circuits traverse a common card
Caution
and use the same VLAN.
E-Series port-mapped mode does not support STP (IEEE 802.1D).
Note

E-Series Multi-Instance Spanning Tree and VLANs

The ONS node can operate multiple instances of STP to support VLANs in a looped topology. You can
dedicate separate circuits across the SONET/SDH ring for different VLAN groups. Each circuit runs its
own STP to maintain VLAN connectivity in a multi-ring environment.

Spanning Tree on a Circuit-by-Circuit Basis

You can also disable or enable STP on a circuit-by-circuit basis on single-card EtherSwitch E-Series
cards in a point-to-point configuration. This feature allows customers to mix spanning tree protected
circuits with unprotected circuits on the same card. It also allows two single-card EtherSwitch E-Series
cards on the same node to form an intranode circuit.

E-Series Spanning Tree Parameters

Default STP parameters are appropriate for most situations
Assistance Center (Cisco TAC) before you change the default STP parameters. See the
Documentation and Submitting a Service Request" section on page xxxviii
contact Cisco TAC.
Table 23-4
Parameter
BridgeID
TopoAge
TopoChanges
DesignatedRoot
RootCost
RootPort
MaxAge
HelloTime
HoldTime
ForwardDelay
Cisco ONS 15454 and Cisco ONS 15454 SDH Ethernet Card Software Feature and Configuration Guide, R8.0
23-22
Spanning Tree Parameters
Description
ONS node unique identifier that transmits the configuration bridge protocol data
unit (BPDU); the bridge ID is a combination of the bridge priority and the ONS
node MAC address.
Amount of time in seconds since the last topology change.
Number of times the STP topology has been changed since the node booted up.
Identifies the STP's designated root for a particular STP instance.
Identifies the total path cost to the designated root.
Port used to reach the root.
Maximum time that received-protocol information is retained before it is discarded.
Time interval, in seconds, between the transmission of configuration BPDUs by a
bridge that is the spanning tree root or is attempting to become the spanning tree
root.
Minimum time period, in seconds, that elapses during the transmission of
configuration information on a given port.
Time spent by a port in the listening state and the learning state.
Chapter 23 E-Series and G-Series Ethernet Operation
(Table 23-4). Contact the Cisco Technical
for information on how to
"Obtaining