What is Cisco IOS?
Cisco IOS (Internetwork Operating System) is an operating system that runs on Cisco routers, switches, and other networking devices. It provides the core functionality for Cisco devices including:
- Routing protocols like OSPF, BGP, EIGRP for routing traffic across networks
- Switching functions for bridging traffic within a LAN
- Security features like firewalls, VPNs, and access controls
- QoS (Quality of Service) for managing bandwidth and prioritizing traffic
- Management tools for monitoring, configuring, and maintaining the network
Cisco IOS provides a consistent set of features across Cisco's routing, switching, wireless, security and other product lines. It is a proprietary operating system that is optimized for Cisco hardware. Many network administrators are familiar with the Cisco IOS CLI (command line interface) that provides text-based access for configuring and managing devices.
Newer versions of Cisco IOS support automation and programmability through modern APIs and instrumentation. This allows network operations teams to streamline management by interfacing with Cisco IOS using common tools like Python and Ansible.