ISR4451-X/K9 with 4 GE and 3 NIM slots

Cisco ISR4451-X/K9 - Overview

The Cisco ISR4451-X/K9 is a high-performance 2RU modular router from the Cisco 4450 Series, designed for large branch offices, regional hubs, and enterprise WAN edge deployments. Compared to the ISR4431, it delivers significantly higher throughput, expansion capacity, and resiliency. With Cisco IOS XE software, the ISR4451-X/K9 supports SD-WAN, advanced routing, and modular services, making it a converged platform for secure, application-aware WAN connectivity.

🔧 Key Hardware Specifications

• Form Factor: 2RU rack-mountable router
• Performance:
  • 1 Gbps default throughput
  • Upgradeable to 2 Gbps or 4 Gbps with performance licenses
• Interfaces:
  • 4x RJ45/SFP combo Gigabit Ethernet WAN/LAN ports
  • 3x NIM (Network Interface Module) slots
  • 2x SM-X (Service Module) slots
  • 1x ISC (Internal Services Card) slot
• Memory/Storage:
  • 4 GB DRAM (upgradeable to 16 GB)
  • 8 GB flash (upgradeable to 32 GB)
• Software: Runs Cisco IOS XE
• Power: Dual redundant PSU options available

🧩 Ideal Use Cases

• Large branch or regional offices requiring high-throughput WAN edge
• Enterprises deploying hybrid WAN and SD-WAN with application-aware routing
• Organizations consolidating routing, security, and modular services into a single ISR platform
• Retail or distributed sites needing scalable WAN connectivity with redundancy