What is EOS (Extensible Operating System), and what are its benefits?

EOS, or Extensible Operating System, is a network operating system developed by Arista Networks for use in their line of data center and cloud networking switches. EOS is designed to provide a stable, modular, and programmable platform for building and managing high-performance networking infrastructures. Here are some key aspects and benefits of EOS:

1. Modularity and Extensibility:

   • EOS is built with a modular architecture that allows for easy customization and extensibility. It consists of a Linux-based kernel and a modular software architecture that separates data plane processing (forwarding) from control plane processing (routing, switching, and management). This modular design enables new features, protocols, and applications to be added or updated without disrupting the operation of the entire system.

2. Programmability and Automation:

   • EOS provides extensive support for automation, scripting, and programmability through industry-standard APIs (Application Programming Interfaces) such as eAPI (eXtensible API), JSON-RPC (JavaScript Object Notation - Remote Procedure Call), and gRPC (Google Remote Procedure Call). These APIs allow network operators to automate configuration, monitoring, troubleshooting, and orchestration tasks using scripting languages like Python or tools like Ansible, Puppet, or Chef.

3. Single Software Image:

   • EOS uses a single software image across all hardware platforms, providing consistency and uniformity in feature sets, management interfaces, and operational workflows. This simplifies software deployment, maintenance, and upgrade processes, as network operators only need to manage a single software version for their entire network infrastructure.

4. Distributed State Database:

   • EOS features a distributed state database called SysDB, which maintains the state of the entire network in a centralized, consistent, and fault-tolerant manner. SysDB stores configuration data, operational state, and real-time telemetry information, allowing for a unified and synchronized view of the network across all devices. This facilitates network-wide visibility, troubleshooting, and automation.

5. Cloud Integration:

   • EOS is designed for seamless integration with cloud platforms and orchestration frameworks, such as VMware NSX, OpenStack, Kubernetes, and AWS (Amazon Web Services). It provides native support for VXLAN (Virtual Extensible LAN) and other cloud networking technologies, enabling organizations to build and manage hybrid cloud environments with ease.

6. Advanced Networking Features:

   • EOS offers a rich set of advanced networking features and protocols, including BGP (Border Gateway Protocol), OSPF (Open Shortest Path First), MPLS (Multiprotocol Label Switching), VXLAN, EVPN (Ethernet Virtual Private Network), and segment routing. These features enable organizations to build scalable, resilient, and high-performance networks to support their business-critical applications and workloads.

7. High Availability and Resilience:

   • EOS is designed for high availability and resiliency, with features such as stateful process restart, hitless software upgrades, in-service software rollback, and virtualization-aware networking. These features ensure continuous operation, minimal downtime, and fast recovery from faults or failures in the network infrastructure.