Cisco

Cisco is the defining force in enterprise and service-provider networking, holding the majority of global market share in routing and switching for over four decades. Their portfolio spans every layer — from physical campus switching (Catalyst 9K) and carrier-grade routers (ASR, CRS) to SD-WAN (Viptela), cloud-managed networking (Meraki), and data center fabric (ACI). IOS XE and NX-OS are the industry-standard operating systems that most network engineers learn first. Cisco's security division — encompassing Firepower NGFW, Umbrella DNS-layer security, and Duo MFA — rounds out a full-stack vendor position rarely matched in breadth. Their certifications (CCNA, CCNP, CCIE) are the most widely recognised credentials in networking worldwide.

Routers, switches, Catalyst, Meraki, SD-WAN, DNA Center, and enterprise networking standards.