Руководство По Проектированию для Cisco Cisco Nexus 5010 Switch

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Virtual PortChannel Design

The Cisco Nexus 7000 Series supports 768 hardware PortChannels (usage can be verified with the command

show port-channel capacity). Release notes indicate how many port channels are supported based on

control-plane capacity - that is, depending on how many VLANs are used, how many SVIs, and so on. These

numbers increase as more software optimizations are introduced in new releases.

The Cisco Nexus 7000 Series supports 8-port PortChannels per chassis, which allows a vPC design where you

can have a 16-port PortChannel from the downstream Cisco Nexus 5000 Series device split into two times 8-port

PortChannels on the Cisco Nexus 7000 Series.

vPC Topology Choice

When using the Cisco Nexus 7000 Series in vPC mode, several topologies become possible, including the

following:

●

Using dual-connected access switches, for example, the Cisco Nexus 5000 Series dual- connected to the

Cisco Nexus 7000 Series with PortChannels. (see Design 1 in Figure 4). With this topology, you can create

16-port PortChannels from each Cisco Nexus 5000 Series device toward the Cisco Nexus 7000 Series. If

using FEX in this topology it should be used in straight-through mode (with no support for host vPC).

●

Using Cisco Nexus 5000 Series pairs in vPC mode (refer to chapter 6 for more information) with a unique

PortChannel configured between the Cisco Nexus 5000 Series pair and the Cisco Nexus 7000 Series pair
(see Design 2 in Figure 4). This topology is often referred to as “Double-sided vPC”. With this topology you

can create a unique 16-port PortChannel from the Cisco Nexus 5000 Series pair connecting to the Cisco

Nexus 7000 Series Switches. This topology can support both fabric extender dual-homed (active-active

mode) and fabric extender single-homed (straight-through mode) with or without Host vPC support.

Figure 4. Cisco Nexus 5000 and Cisco Nexus 7000 Connectivity Options