Configuring Virtual Port Channels

vPC Interactions with Other Features

We recommend that you set all the vPC peer link interfaces to the STP network port type so that Bridge Assurance is automatically enabled on all vPC peer links. We also recommend that you do not enable any of the STP enhancement features on VPC peer links.

You must configure a list of parameters to be identical on the vPC peer switches on both sides of the vPC peer link.

STP is distributed; that is, the protocol continues running on both vPC peer switches. However, the configuration on the vPC peer switch elected as the primary switch controls the STP process for the vPC interfaces on the secondary vPC peer switch.

The primary vPC switch synchronizes the STP state on the vPC secondary peer switch using Cisco Fabric Services over Ethernet (CFSoE).

The vPC manager performs a proposal/handshake agreement between the vPC peer switches that sets the primary and secondary switches and coordinates the two switches for STP. The primary vPC peer switch then controls the STP protocol for vPC interfaces on both the primary and secondary switches.

The Bridge Protocol Data Units (BPDUs) use the MAC address set for the vPC for the STP bridge ID in the designated bridge ID field. The vPC primary switch sends these BPDUs on the vPC interfaces.

Note Display the configuration on both sides of the vPC peer link to ensure that the settings are identical. Use the show spanning-treecommand to display information about the vPC.

vPC and ARP

Table synchronization across vPC peers is managed in Cisco NX-OS using the reliable transport mechanism of the Cisco Fabric Services over Ethernet (CFSoE) protocol. To support faster convergence of address tables between the vPC peers, the ip arp synchronize command must be enabled. This convergence is designed to overcome the delay involved in ARP table restoration when the peer-link port channel flaps or when a vPC peer comes back online.

To improve performance, we recommend that you turn on the ARP sync feature. By default, it is not enabled.

To check whether or not ARP sync is enabled, enter the following command:

switch# show running

To enable ARP sync, enter the following command:

switch(config-vpc-domain) # ip arp synchronize

CFSoE

The Cisco Fabric Services over Ethernet (CFSoE) is a reliable state transport mechanism that you can use to synchronize the actions of the vPC peer devices. CFSoE carries messages and packets for many features linked with vPC, such as STP and IGMP. Information is carried in CFS/CFSoE protocol data units (PDUs).

When you enable the vPC feature, the device automatically enables CFSoE, and you do not have to configure anything. CFSoE distributions for vPCs do not need the capabilities to distribute over IP or the CFS regions. You do not need to configure anything for the CFSoE feature to work correctly on vPCs.

You can use the show mac address-tablecommand to display the MAC addresses that CFSoE synchronizes for the vPC peer link.

 

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Cisco Systems N5KC5596TFA manual VPC and ARP, CFSoE, To enable ARP sync, enter the following command

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.