Cisco ISR4331/K9 Integrated Service Router | New, Used or Refurbished

Cisco ISR4331/K9

Cisco ISR4331 router with 3 Gigabit Ethernet ports, 2 Network Interface Module slots, 1 Service Module slot, 4 GB flash memory, 4 GB DRAM (default RAM)


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Cisco ISR4331/K9 router with 3 Gigabit Ethernet ports, 2 Network Interface Module slots, 1 Service Module slot, 4 GB flash memory, 4 GB DRAM (default RAM)

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ISR 4331 Platform Overview

ISR 4331 Port Diagram


The Cisco 4000 series ISRs (Integrated Service Routers) are designed to greatly improve enterprise branch networks routing and network services. Because of their application-aware networking features and a wide array of voice, security and application expansion licenses, the ISR4000 series can be custom fitted to meet the needs of a wide variety of enterprise networks.



ISR 4331 Port Diagram

The Cisco ISR4331/K9 ships with 3 gigabit Ethernet ports, 2 network interface module slots and 1 service module slot. These 3 ports include one dedicated RJ-45 port, one dedicated SFP port, and one dual mode RJ-45/SFP port. This dual mode port can only be used as either copper of SFP at any given time, not both. Because of this, the ISR 4331 has a maximum of 3 usable interfaces, even though 4 are physically present on the unit.

The software on the ISR4331/k9 follows a universal image scheme, providing all possible feature packs in a single image. This allows for future upgrades through security, voice, or application licensing without modification to the routers software version. Additional functionality can also be added to this router through the addition of service modules and interface cards. Addon cards are available for FXO/FXS, Ethernet port adapters, etc.


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Cisco ISR 4331 Router

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ISR4431/K9 Specs
10/100/1000 ports 3
RJ-45 based ports 2
SFP-based ports 2
Enhanced service-module slots 1
NIM slots 2
Default DDR3 DRAM 4 GB
Max memory DDR3 ECC DRAM (combined control/service/data planes) 16 GB
Default flash memory 4 GB
Maximum flash memory 16 GB
External USB 2.0 Slots 1
USB console port type B mini 1
Serial console port – RJ45 1
Serial auxiliary port RJ45 1
Dimensions H x W x D 1.75 x 17.25 x 17.25 in
Form Factor 1 rack unit (1RU)
Weight 13.5 lb (6.2 KG)


FAQs regarding the Cisco ISR 4331


Does this ISR4331/K9 come with a power supply?

Yes, the ISR 4331 has a build-in AC power supply, and ships with a power cable, console cable and Ethernet cable. This ensures you have everything you need to get started with this router included in the box.

Does this ISR4331/K9 come with rack mounts?

Yes it does! Although if you have a requirement for  mounting hardware please email or give us a call for details.

I need a router that will be able to handle full BGP tables. Will the ISR 4331 have enough memory?

That depends – on the current size of the table, and what other tasks you are using your router for. Specifically, if you intend to keep a full routing table, we recommend upgrading the memory on your ISR4331/K9 just to be safe. Because Cisco recommends using matching DIMMs on ISR 4K routers, we encourage you to install two new DIMMs at once. We recommend two MEM-4300-4G DIMMs (8G total) or two MEM-4300-8G DIMMs (16G total), depending on your requirements.

Can I Smart Net this router?

Yes – all of our ISR4331/K9 are ‘clean’, genuine and smartnet eligible. If you have concerns about the exact unit you will be receiving, such as country of origin, smart net status, hardware revision, or other specifics please contact us. We’d be happy to provide any information we can to put your mind at ease!


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