Руководство По Проектированию для Cisco Cisco Nexus 5010 Switch
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Figure 5 shows a variation of Design 2 in Figure 4.
Figure 5. Variation of the Double-Sided vPC Topology of Figure 4 Design 2
Table 1 summarizes the design issues depicted in topologies in Figures 4 and 5.
Table 1.
vPC Topology Choices
All Links Forwarding
Support for Fabric Extender
Dual-Homed
Dual-Homed
Support for Host Port-
Channeling on Fabric Extender
Channeling on Fabric Extender
Design 1
Yes
No
No
Designs 2 and 3
Yes
Yes
Yes
More on Double-Sided vPC Topologies
A Cisco Nexus 5000 Series running in vPC mode that connects to a Cisco Nexus 7000 Series operating in vPC
mode is called a double-sided vPC topology because PortChannels connect two vPC systems.
Consider the diagram in Figure 6, in which the machines are not yet operating in double-sided vPC mode. In this
topology, the Cisco Nexus 7000 Series Switches are configured for vPC mode. Cisco Nexus 5000 Series devices
are also configured in vPC mode to support host PortChannels.
Connectivity between the Cisco Nexus 5000 Series and Cisco Nexus 7000 Series consists of two separate
PortChannels, Po51 and Po52, which you would expect to find in forwarding mode. In reality, either Po51 or Po52
will be blocking.
The reason is that when you configure the Cisco Nexus switches in vPC mode, the peer link is never blocking. So
even if Po51 and Po52 are not configured for vPC, the VLANs they carry are on the peer link, which, by definition,
is always forwarding.