How to Choose Data Center Spine and Leaf Switches?
Updated at Nov 26th 20241 min read
Struggling with network bottlenecks and scalability issues in your data center? Discover how spine and leaf architecture not only reduces traffic congestion but also future-proofs your network for high-speed interconnectivity. This network architecture requires the configuration of corresponding data center switches, and how should spine and leaf switches be selected and configured to function fully? This article will tell you the answer.
Why Do You Need Spine-leaf Architecture?
The spine and leaf network design was introduced in data centers to enhance performance, particularly for handling east-west traffic. By ensuring every leaf switch has a direct connection to every spine switch, it reduces the number of "hops" between devices to just one, which is one of the key advantages over traditional architectures. Below are additional benefits:
Improved Redundancy: Each leaf switch connects to all spine switches, providing better redundancy compared to the traditional three-tier model using Spanning Tree Protocol (STP). Spine and leaf architecture use protocols like TRILL or Shortest Path Bridging (SPB), which allow traffic to flow through multiple available paths, ensuring redundancy without creating loops.
Enhanced Performance: The ability to use multiple network paths simultaneously reduces congestion, unlike STP, where traffic suffers if the single available path is overloaded. Having just one hop between points also creates more direct routes, further improving performance.
Scalability: The architecture is highly scalable, as adding more switches creates additional traffic routes, reducing congestion even in large networks.
Cost Efficiency: By increasing the number of connections each switch can handle, spine and leaf architecture minimizes the number of devices needed, reducing costs for data centers.
Reduced Latency and Congestion: Limiting the maximum number of hops between nodes to two creates more direct traffic paths, improving overall performance and reducing bottlenecks.
Support for Fixed Configuration Switches: Unlike traditional three-tier networks that often require expensive modular chassis switches, spine and leaf networks can use less costly fixed configuration switches without sacrificing performance.
Adaptability Beyond Data Centers: Though designed for data centers, spine and leaf architecture can also be extended to enterprise networks, offering similar benefits. It eliminates the need for STP by using MLAG for redundancy, allowing both links to be active and ensuring continuous uptime in case of a switch failure.
Enhanced Security: FS currently offers switches with the PicOS® operating system. PicOS® supports security functions at the network edge by allowing the installation of security nodes like firewalls on aggregation switches. It also supports SDN, enabling traffic mirroring to security tools for real-time threat detection and mitigation.
What Are Spine and Leaf Switches?
Spine and leaf switches are the two main components of the spine and leaf architecture in data center. Spine switches can be regarded as core switches in a spine and leaf network architecture. However, the difference is that the 100G switches with high port density are sufficient for spine switches. Leaf switches are equivalent to access layer switches. Leaf switches provide network connections to endpoints, servers, and upwards to spine switches.
What Is Spine Switch
Spine switches can handle layer 3 network traffic with high port density for scalability. Each of its L3 ports is dedicated to connecting to an L2 leaf switch and cannot connect or find any servers, access points, or firewalls. Therefore, the number of ports available on the spine switch determines the number of switches at the spine and leaf layers, which in turn determines the maximum number of servers that can be connected to the network.
In a high-density data center network, evenly distributing the uplink connections of leaf switches between the boards of the spine switches and reducing traffic by cross modules can significantly improve the performance of spine switches. Of course, data center spine switches generally need to have a large cache, high capacity, and virtualized performance. They usually need to be equipped with 10G/25G/40G/100G ports and a complete software system, complete protocols, and application functions, such as EVPN-VXLAN, stacking, MLAG, etc., to facilitate rapid network deployment.
What Is Leaf Switch
Leaf switches are commonly used devices in data centers, mainly to control traffic between servers, and forward layer 2 and layer 3 traffic. The number of uplink ports of a leaf switch restricts the number of spine switches it is connected to, and the number of downlink ports determines the number of devices connected to the leaf switch. Generally, the uplink ports support the speed of 40G/100G, while the downlink ports can vary from 10G/25G/40G/50G/100G depending on the model you plan to use.
As server devices continue to grow, it is necessary to select leaf switches that support larger rates and more ports. To prevent link traffic congestion, leaf switches should have an oversubscription ratio of less than 3:1 for uplink and downlink port bandwidth, or apply virtualization technologies to balance link traffic. For related virtualization technologies, like spine switches, they can also add VXLAN, PFC, stacking, or MLAG technologies, and support both IPv4 and IPv6 for better network management and expansion.
Spine and Leaf Switches Recommendation
Consider key factors in the design of your spine and leaf architecture before buying, especially oversubscription rates and the size of your spine and leaf switch. Of course, we also provide a detailed example for your reference. You can click to learn more about it: How to Design Spine-leaf Architecture?
To choose the spine and leaf switch that's right for you, first understand the performance attributes of spine and leaf switches, including port density, virtualization technology, redundant hardware, and more. The switch selection is then tailored to the specific deployment requirements to finalize the network architecture. The following technical areas can help you make critical choices:
Low Latency: Choose switches with small buffer memory to reduce data transmission delays.
High Throughput: Look for non-blocking architecture to enable full-speed traffic across all ports without congestion.
Advanced QoS Features: Implement QoS policies to prioritize critical traffic, ensuring stable performance and minimal latency for key applications.
Reliability and Redundancy: Opt for switches with dual power supplies and cooling systems to ensure uninterrupted operation during failures. And use VRRP or MLAG protocols to boost network resilience and uptime.
Scalability: Modular switches support seamless expansion without affecting performance during growth. And upgradable Firmware: Ensure firmware can be updated to enhance features without replacing hardware.
Programmability: Look for switches supporting NETCONF/YANG or OpenFlow for flexible and custom network configurations.
Automation Tools: Ensure compatibility with tools like Ansible, Puppet, or Chef for automated deployment and management.
Security Features: Select switches with built-in security to detect and mitigate network threats in real-time.
FS data center spine switches come in 1U and 2U sizes, offering low latency, zero packet loss, high throughput, and efficient service forwarding. They feature advanced chips, redundant hot-swappable power supplies and fans, and support for VXLAN, MLAG (VAP), PFC, and ECN. These switches also offer flexible port options, allowing you to choose the number of ports and bandwidth based on business needs.
Products | ||||||
Ports | 32x 100G QSFP28, 2x 10Gb SFP+ | 64x 800G OSFP | 32x 400G QSFP-DD | 64x 100G QSFP28 | 24x 200G QSFP56, 8x 400G QSFP-DD | 64x 400G QSFP-DD |
CPU | Intel® Xeon® D-1518 processor quad-core 2.2 GHz | Intel Xeon D-1734NT (4-core 8-thread processor with a clock speed of 2.2GHz) | Intel® Xeon® Processor D-1518 4-Core | Intel® Xeon D-1518 processor quad-core 2.2GHz | Intel® Xeon® Processor D-1627 4-core 2.9GHz | Intel® Xeon® Processor D-1627 4-core 2.9GHz |
Switch Chip | Broadcom BCM56870 Trident III | BCM78900 Tomahawk 5 | BCM56980 Tomahawk 3 | Broadcom BCM56970 Tomahawk 2 | BCM56780 Trident 4 | BCM56990 Tomahawk 4 |
Switching Capacity | 6.4 Tbps full duplex | 102.4 Tbps | 25.6 Tbps | 6.4Tbps | 16 Tbps | 51.2 Tbps |
Forwarding Rate | 2980 Mpps | 21200Mpps | 5210 Mpps | 4.2 bpps | 5350 Mpps | 10300 Mpps |
Number of VLANs | 4K | 4K | 4K | 4K | 4K | 4K |
Memory | DRAM 2x 8 GB SO-DIMM DDR4 | SDRAM 16GB | DDR4: 8 GB x 2 SO-DIMM | 8GB SO-DIMM DDR4 RAM with ECC | SDRAM 16GB | SDRAM 32GB |
Flash Memory | 64GB | 240GB (SSD) | m.2 64GB MLC | 32GB | 240GB | 240GB（SSD） |
FS data center leaf switches provide high-performance switches with 10G/25G/40G/100G/400G ports to meet the diverse requirements for the number of uplink ports and downlink ports. They also apply related technologies to meet the increasing data demand:
Virtualization Technologies: ensuring zero packet loss, low latency, and non-blocking lossless Ethernet for reliable network performance.
Software Technologies: FS leaf switches include Layer 3 IPv4/IPv6 routing protocols, VXLAN, and MLAG, enhancing flexibility and scalability.
Products | ||||||
Ports | 48x 25G SFP28, 2x 10Gb SFP+, 8x 100G QSFP28 | 48x 10G SFP+, 6x 40G QSFP+ | 48x 10G RJ45, 6x 100G QSFP28 | 32x 400G QSFP-DD | 24x 200G QSFP56, 8x 400G QSFP-DD | 64x 400G QSFP-DD |
CPU | Intel® Xeon® D-1518 processor quad-core 2.2 GHz | Intel Atom C2538 processor quad-core 2.4GHz | Intel Atom C3558 2.2GHz 4-Core x86 processor | Intel® Xeon® Processor D-1518 4-Core | Intel® Xeon® Processor D-1627 4-core 2.9GHz | Intel® Xeon® Processor D-1627 4-core 2.9GHz |
Switch Chip | Broadcom BCM56873 Trident III | Broadcom BCM56864 Trident II+ | Broadcom BCM56771 Trident 3 | BCM56980 Tomahawk 3 | BCM56780 Trident 4 | BCM56990 Tomahawk 4 |
Switching Capacity | 4 Tbps full duplex | 1.44 Tbps full duplex | 1.08 Tbps | 25.6 Tbps | 16 Tbps | 51.2 Tbps |
Forwarding Rate | 2000 Mpps | 1000 Mpps | 964.28 Mpps | 5210 Mpps | 5350 Mpps | 10300 Mpps |
Number of VLANs | 4K | 4K | 4K | 4K | 4K | 4K |
Memory | DRAM 2x 8 GB SO-DIMM DDR4 | DRAM 8GB SO-DIMM DDR3 RAM with ECC | 2x 8 GB SO-DIMM | DDR4: 8 GB x 2 SO-DIMM | DRAM 16GB | SDRAM 32GB |
Flash Memory | 64GB | 32GB | 64GB | m.2 64GB MLC | 240GB | 240GB（SSD） |
FS PicOS® spine and leaf switches use the unified PicOS® software, offering essential Layer 2/3 protocols and telemetry APIs to enhance network performance and management. They support the AmpCon™ management platform for unified automation and operations, delivering more resilient and efficient network operations at a lower cost for data center networks.
Summary
High-density data centers demand high-performance, scalable switches. FS PicOS® data center switches, with full L2/L3 protocol support and virtualization technology, perfectly embody the benefits of spine-leaf architecture, delivering low latency and seamless scalability through efficient east-west traffic management. Choose FS switches to power up your network’s performance and future growth