DELL N3000 User Manual
758
Configuring the Spanning Tree Protocol
RSTP-PV Aggregation Layer Switch Configuration Example
In this configuration example, two aggregation-layer switches are configured.
Ports 1–4 are configured in a LAG connecting the two aggregation-layer
switches. Ports 12–24 are configured as down-links to twelve access layer
switches configured as in the previous example. Down-links to the access-
layer switches have physical diversity; there is one downlink to each of the
twelve access-layer switches from each of the paired aggregation-layer
switches.
The uplink ports to the network core are configured as LAGs to provide link
The uplink ports to the network core are configured as LAGs to provide link
redundancy. It is presumed that the core links connect to a router running
RSTP-PV. The configuration for the two aggregation-layer switches is
identical, except for the diversity configuration noted below.
For forwarding diversity, the even numbered switch is made the root for the
For forwarding diversity, the even numbered switch is made the root for the
even-numbered VLANs. The odd numbered switch is made the root for the
odd-numbered VLANs.
1 Create VLANs 2 through 4:
console#configure
console(config)#vlan 2-4
console(config-vlan2-4)#exit
2 Enable RSTP-PV:
console(config)#spanning-tree mode rapid-pvst
3 Configure for a max network diameter of 4:
console(config)#spanning-tree vlan 1-4 max-age 16
4 Configure one downlink trunk port per downlink switch:
console(config)#interface range te1/0/12-24
console(config-if-Te1/0/12-24)#switchport mode
trunk
exit
5 Configure forwarding diversity for the even numbered switches:
console(config)#spanning-tree vlan 2,4 root
primary
console(config)#spanning-tree vlan 1,3 root
secondary
6 Configure forwarding diversity for the odd numbered switches: