Руководство По Проектированию для Cisco Cisco Nexus 5010 Switch

Page 15 of 32

Address 001b.54c2.80c2

Cost 1000

Port 4146 (port-channel51)

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

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

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

Po51 Root FWD 1000 128.4146 Network P2p

vPC VLANs and non-vPC VLANs

The PortChannel connecting the vPC peers should carry all the VLANs used by the vPC member ports.

In addition, it is possible to carry also the VLAN used by orphaned ports with some special considerations.

As a general best practice, the VLANs you use for vPC-connected devices should be different from those you use

for single-port attached devices (orphaned ports), and you should put those VLANs (the non-vPC VLANs) on a
trunk that’s different from the one on which the peer link resides.

On the Cisco Nexus 7000 Series, when carrying vPC and non-vPC VLANs on the peer link, you may want to

exclude the orphaned ports SVIs from the default behavior by using the command dual-active exclude

interface-vlan <non-vPC vlans list>. Alternatively, you can use different VLANs for vPC-connected devices and

single-port attached devices (orphaned ports), and put the non-vPC VLANs and the peer link on different trunks.

This recommendation applies to the aggregation layer only, not to the access layer and the following example

illustrates why you should consider either a separate trunk for non-vPC VLANs or the use of the dual-active

exclude interface-vlan command.

Cisco Nexus 7000 Series Example

Figure 11 illustrates what happens during vPC peer link failure for vPC and non-vPC ports. In the figure, Ethernet

2/10 is not part of a vPC; it operates as a regular spanning-tree port. Port Ethernet 2/10 carries VLAN 40. Port

Ethernet2/9 is a vPC ports and it carries VLAN 50

The sequence of events is as follows:

●

The vPC peer link fails (Po10).

●

Ethernet 2/9 on Agg2 is brought down because it is part of vPC Po51 and belongs to the operational

secondary vPC device.

●

Ethernet 2/10 is not part of a vPC, so it stays up and unblocks (indicated by the green arrow in the figure).

●

SVI VLAN50 (vPC-VLAN) and SVI VLAN 40 (not used for vPC, but trunked on the peer link, and as such,

considered a vPC VLAN) are both brought down on the operational secondary device.