User manual
Table Of Contents
- Cisco ONS 15310-CL and Cisco ONS 15310-MA Ethernet Card Software Feature and Configuration Guide
- Contents
- Preface
- Overview of the ML-Series Card
- CTC Operations on the ML-Series Card
- Initial Configuration of the ML-Series Card
- Configuring Interfaces on the ML-Series Card
- Configuring POS on the ML-Series Card
- Configuring STP and RSTP on the ML-Series Card
- STP Features
- STP Overview
- Supported STP Instances
- Bridge Protocol Data Units
- Election of the Root Switch
- Bridge ID, Switch Priority, and Extended System ID
- Spanning-Tree Timers
- Creating the Spanning-Tree Topology
- Spanning-Tree Interface States
- Spanning-Tree Address Management
- STP and IEEE 802.1Q Trunks
- Spanning Tree and Redundant Connectivity
- Accelerated Aging to Retain Connectivity
- RSTP Features
- Interoperability with IEEE 802.1D STP
- Configuring STP and RSTP Features
- Default STP and RSTP Configuration
- Disabling STP and RSTP
- Configuring the Root Switch
- Configuring the Port Priority
- Configuring the Path Cost
- Configuring the Switch Priority of a Bridge Group
- Configuring the Hello Time
- Configuring the Forwarding-Delay Time for a Bridge Group
- Configuring the Maximum-Aging Time for a Bridge Group
- Verifying and Monitoring STP and RSTP Status
- STP Features
- Configuring VLANs on the ML-Series Card
- Configuring IEEE 802.1Q Tunneling and Layer 2 Protocol Tunneling on the ML-Series Card
- Configuring Link Aggregation on the ML-Series Card
- Configuring IRB on the ML-Series Card
- Configuring Quality of Service on the ML-Series Card
- Understanding QoS
- ML-Series QoS
- QoS on RPR
- Configuring QoS
- Monitoring and Verifying QoS Configuration
- QoS Configuration Examples
- Understanding Multicast QoS and Multicast Priority Queuing
- Configuring Multicast Priority Queuing QoS
- QoS not Configured on Egress
- ML-Series Egress Bandwidth Example
- Understanding CoS-Based Packet Statistics
- Configuring CoS-Based Packet Statistics
- Understanding IP SLA
- Configuring the Switching Database Manager on the ML-Series Card
- Configuring Access Control Lists on the ML-Series Card
- Configuring Resilient Packet Ring on the ML-Series Card
- Understanding RPR
- Configuring RPR
- Connecting the ML-Series Cards with Point-to-Point STS Circuits
- Configuring CTC Circuits for RPR
- Configuring RPR Characteristics and the SPR Interface on the ML-Series Card
- Assigning the ML-Series Card POS Ports to the SPR Interface
- Creating the Bridge Group and Assigning the Ethernet and SPR Interfaces
- RPR Cisco IOS Configuration Example
- Verifying Ethernet Connectivity Between RPR Ethernet Access Ports
- CRC Threshold Configuration and Detection
- Monitoring and Verifying RPR
- Add an ML-Series Card into an RPR
- Delete an ML-Series Card from an RPR
- Cisco Proprietary RPR KeepAlive
- Cisco Proprietary RPR Shortest Path
- Redundant Interconnect
- Configuring Security for the ML-Series Card
- Understanding Security
- Disabling the Console Port on the ML-Series Card
- Secure Login on the ML-Series Card
- Secure Shell on the ML-Series Card
- RADIUS on the ML-Series Card
- RADIUS Relay Mode
- RADIUS Stand Alone Mode
- Understanding RADIUS
- Configuring RADIUS
- Default RADIUS Configuration
- Identifying the RADIUS Server Host
- Configuring AAA Login Authentication
- Defining AAA Server Groups
- Configuring RADIUS Authorization for User Privileged Access and Network Services
- Starting RADIUS Accounting
- Configuring a nas-ip-address in the RADIUS Packet
- Configuring Settings for All RADIUS Servers
- Configuring the ML-Series Card to Use Vendor-Specific RADIUS Attributes
- Configuring the ML-Series Card for Vendor-Proprietary RADIUS Server Communication
- Displaying the RADIUS Configuration
- Configuring Bridging on the ML-Series Card
- CE-100T-8 Ethernet Operation
- Command Reference for the ML-Series Card
- [no] bridge bridge-group-number protocol {drpri-rstp | ieee | rstp}
- clear counters
- [no] clock auto
- interface spr 1
- [no] pos mode gfp [fcs-disabled]
- [no] pos pdi holdoff time
- [no] pos report alarm
- [non] pos trigger defects condition
- [no] pos trigger delay time
- [no] pos vcat defect {immediate | delayed}
- show controller pos interface-number [details]
- show interface pos interface-number
- show ons alarm
- show ons alarm defect {[eqpt | port [port-number] | sts [sts-number] | vcg [vcg-number] | vt]}
- show ons alarm failure {[eqpt | port [port-number] | sts [sts-number] | vcg [vcg-number] | vt]}
- spr-intf-id shared-packet-ring-number
- [no] spr load-balance { auto | port-based }
- spr station-id station-id-number
- spr wrap { immediate | delayed }
- Unsupported CLI Commands for the ML-Series Card
- Using Technical Support
- Index

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Cisco ONS 15310-CL and Cisco ONS 15310-MA Ethernet Card Software Feature and Configuration Guide R8.5
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Chapter 6 Configuring STP and RSTP on the ML-Series Card
STP Features
STP Overview
STP is a Layer 2 link management protocol that provides path redundancy while preventing loops in the
network. For a Layer 2 Ethernet network to function properly, only one active path can exist between
any two stations. Spanning-tree operation is transparent to end stations, which cannot detect whether
they are connected to a single LAN segment or a switched LAN of multiple segments.
When you create fault-tolerant internetworks, you must have a loop-free path between all nodes in a
network. The spanning-tree algorithm calculates the best loop-free path throughout a switched Layer 2
network. Switches send and receive spanning-tree frames, called bridge protocol data units (BPDUs), at
regular intervals. The switches do not forward these frames, but use the frames to construct a loop-free
path.
Multiple active paths among end stations cause loops in the network. If a loop exists in the network, end
stations might receive duplicate messages. Switches might also learn end-station MAC addresses on
multiple Layer 2 interfaces. These conditions result in an unstable network.
Spanning tree defines a tree with a root switch and a loop-free path from the root to all switches in the
Layer 2 network. Spanning tree forces redundant data paths into a standby (blocked) state. If a network
segment in the spanning tree fails and a redundant path exists, the spanning-tree algorithm recalculates
the spanning-tree topology and activates the standby path.
When two interfaces on a switch are part of a loop, the spanning-tree port priority and path cost settings
determine which interface is put in the forwarding state and which is put in the blocking state. The port
priority value represents the location of an interface in the network topology and how well it is located
to pass traffic. The path cost value represents media speed.
Supported STP Instances
The ML-Series card supports the per-VLAN spanning tree (PVST+) and a maximum of
255 spanning-tree instances.
Caution At more than 100 STP instances the STP instances may flap and may result in MAC entries flushed, and
MAC entries learned again and again. This will cause flooding in the network. So it is recommended to
keep the STP instances to be less than 100, to keep system from being unstable.
Bridge Protocol Data Units
The stable, active, spanning-tree topology of a switched network is determined by these elements:
• Unique bridge ID (switch priority and MAC address) associated with each VLAN on each switch
• Spanning-tree path cost to the root switch
• Port identifier (port priority and MAC address) associated with each Layer 2 interface
When the switches in a network are powered up, each functions as the root switch. Each switch sends a
configuration BPDU through all of its ports. The BPDUs communicate and compute the spanning-tree
topology. Each configuration BPDU contains this information:
• Unique bridge ID of the switch that the sending switch identifies as the root switch
• Spanning-tree path cost to the root
• Bridge ID of the sending switch