Solution Architecture

The 3-Stage Fabric with Apstra Data Center Director is an EVPN-VXLAN-based validated design based upon the ERB network architecture. Using an ERB network architecture provides the design increased resilience by assigning specific functions to each device role and ensuring that each device role can be scaled independently of the others. Each network switch participating in the design must occupy one of the three roles:

• Server Leaf Switches

The leaf switch focuses on learning and advertising the local MAC Addresses to other remote switches through the BGP EVPN control plane. This means leaf switches can discover all the “remote” hosts without flooding the overlay with ARP/ND requests.

• Border Leaf Switches

Although a border leaf can function as a server leaf switch, it can also act as a gateway to external networks and hence require DCI features. DCI features include connecting to network overlays such as VMware NSX-T, MACSEC, deep buffers, and so on.

• Spine Switches

The spine switch only performs IP forwarding and relaying of routes to all server and border leaf switches. As a result, spine switches in ERB network architectures are referred to as lean spines.

• Access Switches

The access switches are connected to the leaf switches and form a Layer 2 aggregation tier to provide additional port density for end-hosts. This dedicated access layer offers flexible host connectivity, accommodating specific server-side port constraints where 1GbE or 2.5GbE copper interfaces are required.

The use of an ERB network architecture and the associated switch roles not only simplifies the data center design but also provides flexibility at the leaf layer so that new leaf switches can be introduced as traffic throughput increases. Another aspect of this design is the use of non-modular switches, such as the 1U QFX5130-32CD, which can perform high throughput functions at the leaf layer.

To summarize, the ERB network architecture, which underlies the 3-stage fabric with Apstra Data Center Director, can be thought of as a distributed chassis. In an ERB network, leaf switches are roughly analogous to a “line card” in a traditional modular chassis, while the lean spine means the network fabric is more flexible and resilient than a single modular chassis switch. This creates a network more capable and flexible than a traditional modular chassis-based switch, without requiring the purchase or maintenance of a modular chassis-based switch for most enterprise data center scenarios.

For those data centers looking for scale that can only be achieved with chassis-based switches, the HPE Juniper Networking Validation process does take this into account, validating modular chassis switch combinations in ERB network roles. The result is validated network fabrics that can scale from the needs of individual racks up to serving entire data centers and beyond.

Table 1: Supporting Devices for 3-stage EVPN/VXLAN Fabric (ERB) depicts the hardware in various roles such as spine, leaf, and border leaf. This validated design will walk through the high-level steps required to configure a 3-stage Data center, with QFX5220-32CD switches in the spine role, QFX5130-32CD switches in the border leaf role, and QFX5120-48Y switches in the server leaf role. These switches in these roles are considered the baseline design of this validated design, though other switches are qualified for these roles, as documented in the following.

HPE Juniper Networking Hardware and Software Components

This section describes the HPE Juniper Networking products and software versions for this solution.

The design documented in this validated design is considered the baseline representation for the validated solution. As part of a complete solutions suite, we routinely swap hardware devices with other models during iterative use case testing. Each switch platform validated in this document goes through the same rigorous role-based testing using specified versions of Junos OS and Apstra Data Center Director management software.

Table 1: Supporting Devices for 3-stage EVPN-VXLAN Fabric (ERB)

Table 2: HPE Juniper Networking Software and Version

Validated Functionality

Following lists the features for which 3-Stage Fabric is validated.

Table 3: Apstra Data Center Director Intent Based DC Reference

Table 4: Apstra Configlets for Customized Configuration

Table 5: Apstra Probes