ISR4451-X/K9 – 4×GE WAN/LAN Ports – 2×NIM Slots – ISR 4451-X Router
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ISR4451-X/K9 Description
Cisco ISR4451-X/K9, also known as ISR 4451-X or Cisco 4451 router, is a high-performance branch router in the Cisco 4000 Series. It integrates 4 Gigabit Ethernet ports and 2 × 10 Gigabit SFP+ interfaces, along with 3 NIM slots and up to 2 SM-X slots for advanced service modules. With throughput scalable from 1 Gbps to 2 Gbps under performance licensing, the ISR4451-X supports demanding enterprise branch networks requiring WAN aggregation, SD-WAN, voice, and security services. It supports up to 32 GB DRAM, 32 GB flash, dual power supply redundancy, and advanced PVDM4 DSP options, making it an ideal solution for large branches or regional hubs.
Product Highlights
Quick Specs
|
Parameter |
Specification |
|---|---|
|
GE Ports |
4 × 10/100/1000 (RJ-45/SFP mix) |
|
10GE Ports |
2 × 10GE (SFP+) |
|
NIM Slots |
3 |
|
SM-X Slots |
2 (1 double-wide or 2 single-wide) |
|
On-board PVDM/ISC |
1 |
|
Aggregate Throughput |
1 Gbps base, up to 2 Gbps (licensed) |
|
Default / Max DRAM |
8 GB / 32 GB |
|
Default / Max Flash |
8 GB / 32 GB |
|
Max Power with PoE |
1000 W (with PoE PSU boost) |
|
Rack Units |
2 RU |
|
Weight |
~13 kg |
Key Features
High-Performance Branch Routing
Supports 1–2 Gbps aggregate throughput, making it suitable for large branch offices and regional hubs that need fast and reliable WAN performance.
Flexible Modular Expansion
Offers 3 NIM slots and 2 SM-X slots, allowing integration of WAN, voice, LTE, storage, or UCS-E compute modules for tailored branch services.
Integrated Voice and Collaboration
Onboard ISC for PVDM4 DSP modules provides SRST, conferencing, and transcoding, ensuring voice continuity even during WAN outages.
Advanced WAN Security
Hardware-accelerated VPN and SD-WAN features deliver encrypted tunnels, segmentation, and application visibility for secure and optimized traffic.
High PoE Capacity
With PoE-capable PSU, the router delivers up to 1000 W of power to IP phones, cameras, and wireless access points, enabling converged branch access.
Enterprise-Grade Reliability
Redundant power supply support, robust cooling, and Cisco IOS XE software provide long-term stability and simplified lifecycle management.
Front View
|
1 |
Router fan tray (hidden) behind removable bezel |
2 |
LEDs |
|
3 |
Router power On/Off switch |
4 |
AC power supply unit (PSU0) |
|
5 |
AC power supply unit (PSU1) |
|
|
|
1 |
PSU0: Power supply unit 1 |
2 |
PSU1: Power supply unit 2 |
|
3 |
GE POE: Internal PoE daughter card status |
4 |
FLASH: Compact flash status |
|
5 |
TEMP: Temperature status |
6 |
PWR: Power |
|
7 |
STAT: System status |
8 |
FAN: Fan status |
|
9 |
ISC: Integrated Services Card status |
10 |
POE BOOST: Power over Ethernet boost mode |
|
11 |
POE 1: Power over Ethernet 1status |
12 |
POE 0: Power over Ethernet 0 status |
Rear View
|
1 |
GE 0 management port |
2 |
Auxiliary port |
|
3 |
RJ-45 Gigabit Ethernet port (GE 0/0/0) |
4 |
LEDs for the GE 0/0/0 interface (See Table 1-1 for detailed LED information) |
|
5 |
SFP/Gigabit Ethernet port (GE 0/0/0) |
6 |
SFP/Gigabit Ethernet port (GE 0/0/2) |
|
7 |
LEDs for the GE 0/0/2 interface |
8 |
RJ-45 Gigabit Ethernet port (GE 0/0/2) |
|
9 |
NIM slot 1 (shown with slot divider removed). |
10 |
NIM slot 2 (shown with slot divider removed). |
|
11 |
NIM slot 3 |
12 |
Ground connection |
|
13 |
Enhanced Service Module (SM-X) 2 |
14 |
Enhanced Service Module (SM-X) 1 |
|
15 |
RJ-45 Gigabit Ethernet port GE 0/0/3 |
16 |
LEDs for the GE 0/0/3 interface |
|
17 |
SFP/Gigabit Ethernet GE 0/0/3 |
18 |
SFP Gigabit Ethernet GE 0/0/1 |
|
19 |
LEDs for the GE 0/0/1 interface |
20 |
RJ-45 Gigabit Ethernet port GE 0/0/1 |
|
21 |
Serial console port |
22 |
USB Type B mini port |
|
23 |
USB 0 and USB 1 |
|
|
Application Scenarios
Suited for medium and large offices that require resilient WAN connectivity, application-aware routing, and secure VPN to connect to HQ or cloud services.
Supports secure VPN for sensitive data, compliance-driven connectivity, and integrated voice services for environments where uptime is critical.
Provides modular WAN connectivity, high PoE budgets, and voice survivability, making it suitable for multi-service deployments at mission-critical sites.
Product Comparison
|
Feature |
ISR4451-X/K9 | ||
|---|---|---|---|
|
GE Ports |
4 × 1GE |
4 × 1GE |
4 × 1GE |
|
10GE Ports |
None |
2 × 10GE (SFP+) |
2 × 10GE (SFP+) |
|
NIM Slots |
3 |
3 |
3 |
|
SM-X Slots |
None |
2 (1 double-wide) |
3 |
|
On-board PVDM/ISC |
1 |
1 |
1 |
|
DRAM Default / Max |
4 / 16 GB |
8 / 32 GB |
8 / 32 GB |
|
Flash Default / Max |
8 / 32 GB |
8 / 32 GB |
8 / 32 GB |
|
Aggregate Throughput |
500 Mbps – 1 Gbps |
1 – 2 Gbps |
1.5 – 3 Gbps |
|
Max PoE with PSU |
250 W |
1000 W |
1450 W |
|
Rack Units |
1 RU |
2 RU |
3 RU |
|
Weight |
~6.2 kg |
~13 kg |
~13 kg |
ISR4451-X/K9 Supported Modules
|
Module Type / Part Numbers |
Supported on ISR4451-X/K9 |
|---|---|
|
Network Interface Modules (NIMs) |
Yes – 3 slots |
|
NIM-1GE-CU-SFP / NIM-2GE-CU-SFP |
Yes |
|
NIM-1MFT-T1/E1 / NIM-2MFT-T1/E1 |
Yes |
|
NIM-4MFT-T1/E1 / NIM-8MFT-T1/E1 |
Yes |
|
NIM-1CE1T1-PRI / NIM-2CE1T1-PRI |
Yes |
|
NIM-ES2-8 / NIM-ES2-8-P |
Yes (PoE requires PoE PSU) |
|
NIM-SSD / NIM-HDD |
Yes |
|
LTE / xDSL NIM variants |
Yes |
|
Service Modules (SM-X) |
Yes – 2 slots (1 double-wide supported) |
|
UCS-E Compute/Virtualization Modules |
Yes |
|
On-board PVDM4 / ISC |
Supported |
|
SFP/SFP+ Modules |
Supported (1G and 10G optics) |
|
Legacy WIC/EHWIC |
Not supported |
Specifications
| Parameter | Specification | Parameter | Specification |
|---|---|---|---|
| Model | ISR4451-X (Cisco 4000 Series ISR) | Form Factor | 2RU rack-mount |
| GE Ports | 4 × 10/100/1000 (RJ-45/SFP mix) | 10GE Ports | 2 × 10GE SFP+ |
| NIM Slots | 3 | SM-X Slots | 2 (1 double-wide) |
| On-board ISC | 1 slot for PVDM4 DSPs | USB Ports | 2 × USB 2.0 Type-A, 1 × mini-USB console |
| Console / AUX | RJ-45 console and RJ-45 auxiliary | Operating System | Cisco IOS XE |
| DRAM Default / Max | 8 GB / 32 GB | Flash Default / Max | 8 GB / 32 GB |
| Aggregate Throughput | 1 Gbps base, 2 Gbps licensed | Encryption | Hardware-assisted VPN and SD-WAN |
| WAN/LAN via Modules | NIMs for Serial, T1/E1 PRI, xDSL, LTE, EtherSwitch | SFP Support | 1000 Mbps and 10G optics supported |
| Power Supply | AC/DC options, redundant PSU supported | Max PoE Budget | Up to 1000 W with PoE PSU boost |
| Cooling | Integrated fan system | Operating Temp | 0–40 °C |
| Humidity | 5%–85% non-condensing | Altitude | 0–10,000 ft |
| Dimensions (H×W×D) | 3.5 × 17.25 × 18.5 in (88.9 × 438 × 470 mm) | Weight | ~13 kg |
| Compliance | IEC/EN/UL 60950-1/62368-1, CISPR 22/24 Class A | Licensing | Performance, Security, UC, AppX |
Get More Information
Need pricing, stock, or shipping details for the ISR4451-X/K9 ? Layer23-Switch can help you check current availability, lead time, and delivery options for this. Send us the part number, quantity, and destination country via live chat or email sales@layer23-switch.com for a fast quotation.
Quality Certifications
Customer Reviews
Questions & Answers
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What is ISR4451-X/K9 used for?
-
What throughput can ISR4451-X/K9 reach?
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How many onboard Gigabit Ethernet ports does ISR4451-X/K9 have?
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What module slots does ISR4451-X/K9 provide?
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How is ISR4451-X/K9 different from ISR4431/K9?
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How is ISR4451-X/K9 different from ISR4461/K9?
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Does ISR4451-X/K9 support redundant power?
-
What memory is listed for ISR4451-X/K9?
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Anyone weighing the risk of ordering from Layer23 — go for it. Took a little longer to clear customs than expected, otherwise excellent.
Even our most cautious engineer couldn’t find any reason to question this unit.
Delivery to our campus was right on schedule.
Impressive. Most impressive. The power of this router is undeniable.
The 4451-X is a beast. 2Gbps throughput verified. Using it for CUBE/Voice gateway.