Vpc Topology - Cisco 7604-RSP720C-R Configuration Manual

Chapter 7 Configuring vPCs
Information About vPCs
S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m
mode to configure port channels in each vPC, which ensures an optimized, graceful recovery in a
port-channel failover scenario and provides configuration checks against configuration mismatches
among the port channels themselves.
The vPC peer devices use the vPC domain ID that you configure to automatically assign a unique vPC
system MAC address. Each vPC domain has a unique MAC address that is used as a unique identifier
for the specific vPC-related operations, although the devices use the vPC system MAC addresses only
for link-scope operations, such as LACP. We recommend that you create each vPC domain within the
contiguous Layer 2 network with a unique domain ID. You can also configure a specific MAC address
for the vPC domain, rather than having the Cisco NX-OS software assign the address.
See the "CFSoE" section on page 7-26 for more information on displaying the vPC MAC table.
After you create a vPC domain, the Cisco NX-OS software creates a system priority for the vPC domain.
You can also configure a specific system priority for the vPC domain.
Note When manually configuring the system priority, you must ensure that you assign the same priority value
on both vPC peer devices. If the vPC peer devices have different system priority values, vPC will not
come up.

vPC Topology

Figure 7-9 shows a basic configuration in which the Cisco Nexus 7000 Series Switch ports are directly
connected to another switch or host and are configured as part of a port channel that becomes part of a
vPC.
Figure 7-9 Switch vPC Topology
mgmt0 mgmt0
Eth1/10 Eth2/1
P020
vPC20
In the figure, vPC 20 is configured on port channel 20, which has Eth1/10 on the first switch and Eth2/1
on the second as member ports.
Beginning with Cisco NX-OS Release 5.2(1), you can configure a vPC from the peer devices through
Fabric Extenders (FEXs), as shown in Figure 7-10.
Cisco Nexus 7000 Series NX-OS Interfaces Configuration Guide, Release 5.x
7-14
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