Skip to main content

Leaf-spine

Leaf-spine is a two-layer network topology composed of leaf switches and spine switches.
Leaf-spine is a two-layer data center network topology that's useful for data centers that experience more east-west network traffic than north-south traffic. The topology is composed of leaf switches (to which servers and storage connect) and spine switches (to which leaf switches connect). Leaf switches mesh into the spine, forming the access layer that delivers network connection points for servers.

Every leaf switch in a leaf-spine architecture connects to every switch in the network fabric. No matter which leaf switch a server is connected to, it has to cross the same number of devices every time it connects to another server. (The only exception is when the other server is on the same leaf.) This minimizes latency and bottlenecks because each payload only has to travel to a spine switch and another leaf switch to reach its endpoint. Spine switches have high port density and form the core of the architecture.

A leaf-spine topology can be layer 2 or layer 3 depending upon whether the links between the leaf and spine layer will be switched or routed. In a layer 2 leaf-spine design, Transparent Interconnection of Lots of Links or shortest path bridging takes the place of spanning-tree. All hosts are linked to the fabric and offer a loop-free route to their Ethernet MAC address through a shortest-path-first computation. In a layer 3 design, each link is routed. This approach is most efficient when virtual local area networks are sequestered to individual leaf switches or when a network overlay, like VXLAN, is working.


Comments

Popular posts from this blog

Ghosting

Ghosting is to cease communications without notification. The use of the word "ghost" as a verb originated in social media in reference to dating, but the term is now used by employers to describe employees and potential employees who suddenly disappear. Typically, ghosting is used to describe: Job candidates who suddenly stop responding to messages. New hires who fail to show up for their first day of work. Employees who do not show up for a shift. Employees who leave work in the middle of the day and never come back. Some analysts blame ghosting on millennial entitlement. The reasoning is that members of the millennial generation have been brought up to feel they are special -- so special, in fact, that they do not need to follow conventional rules of behavior. Other analysts, however, maintain that ghosting behavior stems from changes in the job market and the phenomenon is simply a reflection of the laws of supply and demand in a healthy jo...

Data deduplication

Data deduplication -- often called intelligent compression or single-instance storage -- is a process that eliminates redundant copies of data and reduces storage overhead. Data deduplication techniques ensure that only one unique instance of data is retained on storage media, such as disk, flash or tape. Redundant data blocks are replaced with a pointer to the unique data copy. In that way, data deduplication closely aligns with incremental backup, which copies only the data that has changed since the previous backup. For example, a typical email system might contain 100 instances of the same 1 megabyte (MB) file attachment. If the email platform is backed up or archived, all 100 instances are saved, requiring 100 MB of storage space. With data deduplication, only one instance of the attachment is stored; each subsequent instance is referenced back to the one saved copy. In this example, a 100 MB storage demand drops to 1 MB. Target vs. source deduplication Data deduplica...

A Graphics Processing Unit (GPU)

A graphics processing unit (GPU) is a computer chip that performs rapid mathematical calculations, primarily for the purpose of rendering images. A GPU may be found integrated with a central processing unit (CPU) on the same circuit, on a graphics card or in the motherboard of a personal computer or server. In the early days of computing, the CPU performed these calculations. As more graphics-intensive applications such as AutoCAD were developed; however, their demands put strain on the CPU and degraded performance. GPUs came about as a way to offload those tasks from CPUs, freeing up their processing power. NVIDIA, AMD, Intel and ARM are some of the major players in the GPU market. GPU vs. CPU A graphics processing unit is able to render images more quickly than a central processing unit because of its parallel processing architecture, which allows it to perform multiple calculations at the same time. A single CPU does not have this capability, although multi...