Configuring Virtual Port Channels

vPC Number

Note You must ensure that the two switches connected by the vPC peer link have certain identical operational and configuration parameters.

When you configure the vPC peer link, the vPC peer switches negotiate that one of the connected switches is the primary switch and the other connected switch is the secondary switch. By default, the Cisco NX-OS software uses the lowest MAC address to elect the primary switch. The software takes different actions on each switch—that is, the primary and secondary—only in certain failover conditions. If the primary switch fails, the secondary switch becomes the operational primary switch when the system recovers, and the previously primary switch is now the secondary switch.

You can also configure which of the vPC switches is the primary switch. If you want to configure the role priority again to make one vPC switch the primary switch, configure the role priority on both the primary and secondary vPC switches with the appropriate values, shut down the EtherChannel that is the vPC peer link on both switches by entering the shutdown command, and reenable the EtherChannel on both switches by entering the no shutdown command.

MAC addresses that are learned over vPC links are also synchronized between the peers.

Configuration information flows across the vPC peer links using the Cisco Fabric Services over Ethernet (CFSoE) protocol. All MAC addresses for those VLANs configured on both switches are synchronized between vPC peer switches. The software uses CFSoE for this synchronization.

If the vPC peer link fails, the software checks the status of the remote vPC peer switch using the peer-keepalive link, which is a link between vPC peer switches, to ensure that both switches are up. If the vPC peer switch is up, the secondary vPC switch disables all vPC ports on its switch. The data then forwards down the remaining active links of the EtherChannel.

The software learns of a vPC peer switch failure when the keepalive messages are not returned over the peer-keepalive link.

Use a separate link (vPC peer-keepalive link) to send configurable keepalive messages between the vPC peer switches. The keepalive messages on the vPC peer-keepalive link determines whether a failure is on the vPC peer link only or on the vPC peer switch. The keepalive messages are used only when all the links in the peer link fail.

vPC Number

Once you have created the vPC domain ID and the vPC peer link, you can create EtherChannels to attach the downstream switch to each vPC peer switch. That is, you create one single EtherChannel on the downstream switch with half of the ports to the primary vPC peer switch and the other half of the ports to the secondary peer switch.

On each vPC peer switch, you assign the same vPC number to the EtherChannel that connects to the downstream switch. You will experience minimal traffic disruption when you are creating vPCs. To simplify the configuration, you can assign the vPC ID number for each EtherChannel to be the same as the EtherChannel itself (that is, vPC ID 10 for EtherChannel 10).

Note The vPC number that you assign to the EtherChannel connecting to the downstream switch from the vPC peer switch must be identical on both vPC peer switches.

Cisco Nexus 5000 Series NX-OS Interfaces Configuration Guide, Release 5.2(1)N1(1)

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N5KC5596TFA specifications

The Cisco Systems N5KC5596TFA is a high-performance data center switch designed specifically for modern architectures requiring low-latency, high-bandwidth connectivity. As part of the Nexus 5000 series, the N5KC5596TFA addresses the needs of virtualized environments, cloud computing, and highly dynamic workloads, making it an essential choice for enterprises and service providers.

One of the standout features of the N5KC5596TFA is its impressive port density. The switch offers 48 10 Gigabit Ethernet (10GbE) ports and 4 40 Gigabit Ethernet (40GbE) uplinks, providing flexibility to connect a variety of devices and ensuring high throughput across the network. This port configuration is ideal for connecting multiple servers and storage devices, making it perfect for environments with significant data traffic.

The switch supports a range of advanced technologies such as Virtual Extensible LAN (VXLAN) for improving scalability and multi-tenancy in data center networks. VXLAN encapsulates Layer 2 Ethernet frames within Layer 4 UDP packets, allowing for a larger address space and effective overlay networking, which is crucial for cloud deployments.

Another notable aspect of the N5KC5596TFA is its support for Data Center Bridging (DCB), which enhances the reliability and performance of Ethernet networks. DCB features like Priority Flow Control (PFC) and Enhanced Transmission Selection (ETS) help to minimize data loss and ensure Quality of Service (QoS) for various types of traffic, including storage and regular data, which is critical in a converged infrastructure.

Security is also a priority with the N5KC5596TFA, as it comes equipped with features such as Access Control Lists (ACLs) and port security, helping to safeguard the network from unauthorized access and potential threats.

In terms of management, the switch offers integration with Cisco's Data Center Network Manager (DCNM), providing tools for monitoring, management, and automation, which simplifies operational tasks. Additionally, it supports Cisco's Application Centric Infrastructure (ACI), enabling a more comprehensive and application-focused approach to networking.

Overall, the Cisco Systems N5KC5596TFA is engineered for organizations looking to build robust, highly efficient, and secure data center environments. Its combination of high density, versatile connectivity options, and advanced networking technologies makes it a powerful solution for meeting the demands of today’s enterprise workloads.
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