ISR4221/K9 router with 2 GB ethernet ports

Cisco ISR4221/K9 - Overview

The ISR 4221 is an entry-level model in the Cisco 4000 Series Integrated Services Routers (ISR 4K). It was built to provide secure, high-performance WAN connectivity for distributed enterprises with lean IT resources.

🔧 Key Specifications

• Form Factor: 1RU rack-mountable router
• Performance:
  • Up to 35 Mbps default throughput, software-upgradeable to 75 Mbps
  • Optimized for SD-WAN and application-aware routing
• Interfaces:
  • 1x RJ45/SFP combo Gigabit Ethernet WAN/LAN ports
  • 1x RJ45 Gigabit Ethernet LAN port
  • 2x NIM (Network Interface Module) slot
    
• Memory/Storage:
  • 4 GB DRAM (upgradeable to 8 GB)
  • 8 GB flash
• Power: AC, redundant PSU not supported on this model
• Software: Runs Cisco IOS XE (modular, Linux-based OS)
• Security:
  • Integrated Zone-Based Firewall
  • VPN (IPsec, DMVPN, FlexVPN)
  • Trustworthy Systems features (secure boot, image signing)

🧩 Ideal Use Cases

• Small branch offices needing secure WAN connectivity
• SD-WAN deployments with centralized policy and application optimization
• Retail or remote sites with lean IT staff
• Migration path from ISR G2 routers (e.g., 1900/2900 series)