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Cisco ONS 15310-CL, ONS 15310-MA, and ONS 15310-MA SDH Ethernet Card Software Feature and Configuration Guide, R9.1 and R9.2
78-19415-01
Chapter 7 Configuring STP and RSTP on the ML-Series Card
Configuring STP and RSTP Features
Default STP and RSTP Configuration
Table 7-5 shows the default STP and RSTP configuration.
Disabling STP and RSTP
STP is enabled by default on the native VLAN 1 and on all newly created VLANs up to the specified
spanning-tree limit of 255. Disable STP only if you are sure there are no loops in the network topology.
Caution
STP edge ports are bridge ports that do not need STP enabled—where loop protection is not needed out
of that port or an STP neighbor does not exist out of that port. For RSTP, it is important to disable STP
on edge ports, which are typically front-side Ethernet ports, using the command bridge
bridge-group-number spanning-disabled on the appropriate interface. If RSTP is not disabled on edge
ports, convergence times will be excessive for packets traversing those ports.
Caution
When STP is disabled and loops are present in the topology, excessive traffic and indefinite packet
duplication can drastically reduce network performance.
Beginning in privileged EXEC mode, follow these steps to disable STP or RSTP on a per-VLAN basis:
Table 7-5 Default STP and RSTP Configuration
Feature Default Setting
Enable state Up to 255 spanning-tree instances
can be enabled.
Switch priority 32768 + Bridge ID
Spanning-tree port priority (configurable on a per-interface
basis—used on interfaces configured as Layer 2 access ports)
128
Spanning-tree port cost (configurable on a per-interface basis) 100 Mbps: 19
10 Mbps: 100
STS-1: 37
Hello time 2 seconds
Forward-delay time 15 seconds
Maximum-aging time 20 seconds
Command Purpose
Step 1
ML_Series# configure terminal
Enters the global configuration mode.
Step 2
ML_Series(config)# interface
interface-id
Enters the interface configuration mode.
Step 3
ML_Series(config-if)# bridge-group
bridge-group-number
spanning disabled
Disables STP or RSTP on a per-interface basis.
Step 4
ML_Series(config-if)# end
Returns to privileged EXEC mode.