Cisco Cisco Nexus 5010 Switch Guía De Diseño

Page 14 of 32

●

Be sure to preprovision MST. Create the region configuration for the deployment as well as all the VLAN

mappings. VLAN creation and assignment to trunk links and host ports can be performed after the

deployment with no disruption. Region modifications should be limited to the deployment time to reduce the

need for topology recalculations and the need to deal with Type-1 misconfigurations.

●

At the aggregation layer, create a root or a secondary root device as usual. Matching root and primary vPC

switch is preferred.

●

Make sure pathcost method long is enabled.

Prior to configuring vPCs, the spanning-tree configuration on the access layer appears with Nexus7k01 (agg1) as

the root switch on port Ethernet2/1 and with Nexus7k02 (agg2) as the secondary root switch on port Ethernet2/2.

The following output illustrates the connectivity from the Cisco Nexus 5000 Series to the Cisco Nexus 7000 Series
and the “show spanning-tree” command illustrates the spanning-tree topology.

tc-nexus5k01# show cdp neigh

Device-ID Local Intrfce Hldtme Capability Platform Port ID

tc-nexus7k01-vdc2(TBM12162254)Eth2/1 133 R S I s N7K-C7010 Eth2/9

tc-nexus7k02-vdc2(TBM12193229)Eth2/2 175 R S I s N7K-C7010 Eth2/9

tc-nexus5k01# show spanning-tree vlan 50

VLAN0050

Spanning tree enabled protocol rstp

Root ID Priority 24626

Address 001b.54c2.80c2

Cost 2000

Bridge ID Priority 32818 (priority 32768 sys-id-ext 50)

Address 000d.eca3.477c

Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Interface Role Sts Cost Prio.Nbr Type

---------------- ---- --- --------- -------- --------------------------------

Eth2/1 Root FWD 2000 128.257 Network P2p

Eth2/2 Altn BLK 2000 128.258 Network P2p

The direct path to the root has a cost of 2000, while the alternate path (indicated as blocking) offers a cost of 3000

which indicates a path made of two hops: first a 10 Gigabit Ethernet link and then a two times 10 Gigabit Ethernet

link PortChannel.

After configuring the vPCs, the two Cisco Nexus 7000 Series Switches appear as a single switching device from a

spanning-tree perspective (remember that the vPC primary is the Cisco Nexus 7000 Series Switch that processes

BPDUs). The following output illustrates the Spanning-Tree topology after the vPC configuration.

tc-nexus5k01# show spanning-tree vlan 50

VLAN0050

Spanning tree enabled protocol rstp

Root ID Priority 24626