ISR4451-X-SEC/K9 – Integrated Services Router with Advanced Security
Product Overview
The Cisco ISR4451-X-SEC/K9 is a next-generation Integrated Services
Router from the Cisco 4000 Series, designed for high-performance
WAN, branch, and security-focused deployments. This model includes
a security license, enabling advanced features like IPsec VPN,
zone-based firewall, and SSL VPN. With modular scalability up to 2
Gbps performance, the ISR4451-X-SEC/K9 delivers application-aware
routing, SD-WAN readiness, and unified communications, all in a 2RU
form factor.
Product Details
| Specification | Description |
|---|---|
| Product Code | ISR4451-X-SEC/K9 |
| Series | Cisco ISR 4000 Series |
| Form Factor | 2RU rack-mountable |
| Performance | Base: 1 Gbps (upgradable to 2 Gbps via license) |
| Integrated Ports | 4 x 1G RJ45, 1 x RJ45 Console, 1 x USB |
| NIM Slots | 3 x Network Interface Module slots |
| SM Slots | 2 x Service Module slots |
| DRAM | 4 GB (upgradeable to 16 GB) |
| Flash Storage | 8 GB (upgradeable) |
| Power Supply | Dual redundant optional |
| Software | Cisco IOS XE |
| VPN & Security Features | IPsec, SSL VPN, Zone-Based Firewall |
| SD-WAN Support | Yes |
| Voice & Video Support | Yes (with UC license) |
| High Availability | Yes (NSF, ISSU, power redundancy) |
Product Features
Integrated SEC (Security) license enables ZBFW, IPsec, SSL VPN, and control plane protection
Modular design with NIM and SM slots for WAN, switch, LTE, and voice module expansion
Delivers up to 2 Gbps performance with performance-on-demand license
Fully SD-WAN ready with support for vManage, application routing, and intelligent path control
Enhanced unified communications support, including voice and video services
Powered by Cisco IOS XE, enabling programmability, automation, and telemetry
Ideal for secure enterprise branches, hybrid WAN deployments, and cloud-first access
Similar Models Comparison
| Model | Base Performance | Max Performance | Security License | SD-WAN Ready | Form Factor |
|---|---|---|---|---|---|
| ISR4451-X-SEC/K9 | 1 Gbps | 2 Gbps | Yes | Yes | 2RU |
| ISR4431-SEC/K9 | 500 Mbps | 1 Gbps | Yes | Yes | 1RU |
| ISR4351-SEC/K9 | 200 Mbps | 400 Mbps | Yes | Yes | 2RU |
| ISR4331-SEC/K9 | 100 Mbps | 300 Mbps | Yes | Yes | 1RU |
Latest Models in Same Series Comparison
| Model | Performance Range | Slots (NIM/SM) | Key Features |
|---|---|---|---|
| ISR4451-X-SEC/K9 | 1–2 Gbps | 3 / 2 | Secure WAN edge, SD-WAN ready |
| ISR4431-SEC/K9 | 500 Mbps–1 Gbps | 2 / 1 | Mid-size branches |
| ISR4351-SEC/K9 | 200–400 Mbps | 2 / 2 | Voice/video, branch redundancy |
