Configuring Virtual Port Channels

vPC Peer Switch

Note Do not enter the no cfs eth distribute or the no cfs distribute command. CFSoE must be enabled for vPC functionality. If you do enter either of these commands when vPC is enabled, the system displays an error message.

When you enter the show cfs application command, the output displays "Physical-eth," which shows the applications that are using CFSoE.

vPC Peer Switch

The vPC peer switch feature addresses performance concerns around STP convergence. This feature allows a pair of Cisco Nexus devices to appear as a single STP root in the Layer 2 topology. This feature eliminates the need to pin the STP root to the vPC primary switch and improves vPC convergence if the vPC primary switch fails.

To avoid loops, the vPC peer link is excluded from the STP computation. In vPC peer switch mode, STP BPDUs are sent from both vPC peer devices to avoid issues related to STP BPDU timeout on the downstream switches, which can cause traffic disruption.

This feature can be used with the pure peer switch topology in which the devices all belong to the vPC.

Note Peer-switch feature is supported on networks that use vPC and STP-based redundancy is not supported. If the vPC peer-link fail in a hybrid peer-switch configuration, you can lose traffic. In this scenario, the vPC peers use the same STP root ID as well same bridge ID. The access switch traffic is split in two with half going to the first vPC peer and the other half to the second vPC peer. With the peer link failed, there is no impact on north/south traffic but east-west traffic will be lost (black-holed).

For information on STP enhancement features and Rapid PVST+, see the Layer 2 Switching Configuration Guide for your device.

Guidelines and Limitations for vPCs

vPC has the following configuration guidelines and limitations:

•You must enable the vPC feature before you can configure vPC peer-link and vPC interfaces.

•You must configure the peer-keepalive link before the system can form the vPC peer link.

•The vPC peer-link needs to be formed using a minimum of two 10-Gigabit Ethernet interfaces.

•You can connect a pair of Cisco Nexus 5000 Series switches or a pair of Cisco Nexus 5500 Series switches in a vPC directly to another switch or to a server. vPC peer switches must be of the same type, for example, you can connect a pair of Nexus 5000 series switches or a pair of Nexus 5500 Series switches but you cannot connect a Nexus 5000 Series switch to a Nexus 5500 Series switch in a vPC topology.

•Only port channels can be in vPCs. A vPC can be configured on a normal port channel (switch-to-switch vPC topology), on a port channel fabric interface (fabric extender vPC topology), and on a port channel host interface (host interface vPC topology).

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

78-26881-OL

79

Page 90 Page 92
Page 91
Image 91
Cisco Systems N5KC5596TFA manual Guidelines and Limitations for vPCs, VPC Peer Switch
Page 90 Page 92

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.
Top Page Image Contents