Cisco CISCO3845-MB

Name: Cisco CISCO3845-MB
Brand: Cisco
SKU: 6256
Price: 125.0 USD
Availability: InStock

Cisco 3845 motherboard

In Stock

US $125.00

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Product Highlights

Family

Routers

Brand

Cisco

Warranty

Lifetime (see details)

Availability

Usually Ships Same Day if Ordered by 1PM PST

What's Included

512MB DRAM (2x MEM3800-256D)
128MB Flash (1x MEM3800-128CF)

When a Cisco 3845 Integrated Services Router experiences a motherboard failure, replacing the entire chassis is costly and disruptive. The CISCO3845-MB is the factory-original, field-replaceable motherboard for the Cisco 3845 ISR, enabling you to restore full router functionality without a complete platform swap.

This motherboard ships with 512MB of DDR SDRAM (2× MEM3800-256D) and 128MB of Compact Flash (1× MEM3800-128CF) pre-installed, so you have the memory and flash storage needed to boot a Cisco IOS image right out of the box. The CISCO3845-MB carries the integrated Gigabit Ethernet interfaces and provides the core processing foundation for the Cisco 3845 platform.

The Cisco 3845 is part of the Cisco 3800 Series of Integrated Services Routers, designed for medium-sized businesses and enterprise branch offices requiring advanced routing, security, voice, and WAN services in a single modular platform. While the Cisco 3800 Series has reached End-of-Life status, these routers remain widely deployed in production networks. Keeping a spare CISCO3845-MB motherboard on hand is a cost-effective way to maintain uptime and extend the service life of your existing Cisco 3845 investment.

Features & Benefits

Field-Replaceable Motherboard

The CISCO3845-MB is a field-replaceable unit (FRU) for the Cisco 3845 router chassis. Rather than replacing an entire router when the motherboard fails, network teams can swap just this component — significantly reducing hardware costs and minimizing the time needed to restore service.

Pre-Installed Memory & Flash

This motherboard ships with 512MB of DDR SDRAM (2× MEM3800-256D) and 128MB of Compact Flash (1× MEM3800-128CF) already installed. This means you can load a Cisco IOS image and bring the router back online without sourcing memory or flash separately.

Integrated Gigabit Ethernet

The Cisco 3845 motherboard provides the onboard 10/100/1000BASE-T Gigabit Ethernet LAN ports that are integral to the router's connectivity. Replacing the motherboard restores these built-in interfaces along with all core routing and processing functions.

Extend Your Cisco 3845 Investment

Although the Cisco 3800 Series has reached End-of-Life, many organizations continue to rely on these routers in production. Stocking a spare motherboard is a practical, budget-friendly strategy to protect against unplanned downtime and extend the operational life of your Cisco 3845 deployment.

Deployment Scenarios

Emergency Motherboard Replacement

When a Cisco 3845 router suffers a motherboard failure at a branch office or remote site, having a CISCO3845-MB on hand allows your team to perform a rapid swap and restore WAN connectivity without waiting for a full chassis replacement.

Spare Parts Inventory for Legacy Networks

Organizations running multiple Cisco 3845 routers across distributed sites can stock the CISCO3845-MB as a critical spare. Since the platform is End-of-Life and new units are no longer available from Cisco, maintaining spare motherboards ensures continued serviceability.

Lab and Test Environments

Network engineers maintaining Cisco 3845 routers in lab or training environments can use the CISCO3845-MB to rebuild or repair units cost-effectively, keeping lab infrastructure functional without investing in newer platforms for legacy IOS testing.

Genuine Cisco Motherboard — Factory-original board designed exclusively for the Cisco 3845 ISR chassis

512MB DRAM Included — Ships with 2x MEM3800-256D DIMMs pre-installed for immediate deployment

128MB Compact Flash Included — Comes with 1x MEM3800-128CF for IOS image storage

Field-Replaceable Design — Swap the motherboard without replacing the entire router chassis, reducing downtime and cost

Integrated Gigabit Ethernet — Motherboard carries the onboard 10/100/1000 LAN ports for the Cisco 3845

Cisco 3800 Series Compatible — Purpose-built for the Cisco 3845 Integrated Services Router platform

General

Manufacturer

Cisco Systems, Inc.

Part Number

CISCO3845-MB

Product Type

Replacement Motherboard (Field-Replaceable Unit)

Compatible Platform

Cisco 3845 Integrated Services Router

Product Family

Cisco 3800 Series ISR

Product Status

End-of-Life (EOL)

Memory

Installed DRAM

512MB (2× MEM3800-256D DDR SDRAM)

Maximum DRAM (Cisco 3845 Platform)

1GB

DRAM Technology

DDR SDRAM with ECC

Installed Flash

128MB (1× MEM3800-128CF Compact Flash)

Maximum Flash (Cisco 3845 Platform)

512MB

Integrated Interfaces (Cisco 3845 Platform)

LAN Ports

2× 10/100/1000BASE-T (RJ-45)

SFP Ports

1× Gigabit Ethernet SFP

Console Port

1× RJ-45 (up to 115.2 kbps)

Auxiliary Port

1× RJ-45 (up to 115.2 kbps)

USB Ports

2× USB 1.1

Expansion Slots (Cisco 3845 Platform)

NME Slots

HWIC Slots

AIM Slots

PVDM Slots

Environmental (Cisco 3845 Platform)

Operating Temperature

0°C to 40°C (32°F to 104°F)

Operating Humidity

5–95%, non-condensing

Compatibility Notes

Compatible Platform:

Cisco 3845 Integrated Services Router (CISCO3845)

Included Memory:

2× MEM3800-256D (256MB DDR SDRAM each, 512MB total)
1× MEM3800-128CF (128MB Compact Flash)

Note: The CISCO3845-MB is designed exclusively for the Cisco 3845 chassis. It is not compatible with the Cisco 3825 or other Cisco router platforms. The Cisco 3845 and the entire Cisco 3800 Series have reached End-of-Life status. No new units or official Cisco support contracts are available from the manufacturer.

Downloads & Resources

Cisco 3800 Series Data Sheet (PDF)

Cisco 3845 Hardware Installation Guide

Cisco 3800 Series EOL Announcement (PDF)

Frequently Asked Questions

The CISCO3845-MB ships with 512MB of DRAM (2× MEM3800-256D) and 128MB of Compact Flash (1× MEM3800-128CF) pre-installed. No power supply, chassis, fans, or additional modules are included.

No. The CISCO3845-MB is designed exclusively for the Cisco 3845 chassis. The Cisco 3825 uses a different motherboard. Always verify the part number matches your specific router model.

Yes. The Cisco 3845 and the entire Cisco 3800 Series have reached End-of-Life. Cisco no longer sells new units or offers official hardware support. However, refurbished and pre-owned spare parts like the CISCO3845-MB remain available through secondary-market suppliers.

Yes. The Cisco 3845 platform supports up to 1GB of DDR SDRAM and up to 512MB of Compact Flash. The CISCO3845-MB ships with 512MB DRAM and 128MB Flash, and both can be upgraded with compatible Cisco memory modules.

They are functionally the same motherboard. The '=' suffix in Cisco's part numbering convention indicates an individually orderable service spare SKU, while the version without '=' typically denotes the part as it ships inside a complete system.

Part Number	Product	Key Difference
CISCO3845	Cisco 3845 ISR (Complete Router)	Full Cisco 3845 router chassis with power supply, fans, and all components — choose this if you need a complete unit rather than just the motherboard.
CISCO3845-MB=	Cisco 3845 Motherboard (Service Spare)	The orderable service-spare variant of the same motherboard — functionally identical to CISCO3845-MB; the '=' suffix denotes the individually orderable spare SKU.
MEM3800-512D	512MB DRAM Upgrade for Cisco 3800	Single 512MB DDR SDRAM DIMM for the Cisco 3800 Series — use this if you only need a memory upgrade, not a full motherboard replacement.
MEM3800-256CF	256MB Compact Flash for Cisco 3800	256MB Compact Flash card for the Cisco 3800 Series — a flash-only upgrade if your motherboard is functional but you need more IOS image storage.