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RAM for Cisco ISR 4431 (ISR4431/K9)

Model Years: 2014–2023

Max RAM: 16GBRAM Slots: 1RAM Type: DDR4 DRAM 2133MHz
⚠ Single Slot — Limited Upgrade

Quick answer

Our data matches the Cisco ISR 4431 (ISR4431/K9) with Cisco 200GB SSD for ISR 4431 (SSD, M.2 SATA, 0MHz, 200GB); Cisco 32GB Flash Memory for ISR 4400 (Flash, CompactFlash, 0MHz, 32GB); Cisco 16GB DDR4 DRAM for ISR 4431 (DDR4 DRAM, DDR4 DIMM, 2133MHz, 16GB), plus 7 more options listed below.

Supported memory profile: DDR4 DRAM, M.2 SATA, 2133MHz, up to 16GB max, 1 slot.

Before buying, confirm your exact model number, memory generation, form factor (M.2 SATA), speed, and maximum supported capacity. Live eBay listings are shown below and may change.

Compatible RAM for the Cisco ISR 4431

Listings and prices are pulled from eBay and may change. Always verify compatibility before purchase. Listings are updated daily.

Cisco 200GB SSD for ISR 4431

SSD-M2-200G

HIGH
SSD0MHz200GBM.2 SATA

Cisco 200GB SSD for ISR 4431

1 listing

Cisco 32GB Flash Memory for ISR 4400

MEM-4400-32G-FLSH

HIGH
Flash0MHz32GBCompactFlash

Cisco 16GB DDR4 DRAM for ISR 4431

MEM-4400-16G

HIGH
DDR4 DRAM2133MHz16GBDDR4 DIMM

Cisco 8GB Flash for ISR 4431

MEM-4400-8G-FLSH

HIGH
Flash0MHz8GBCompactFlash

Cisco 8GB Flash for ISR 4431

2 listings

Kingston 16GB DDR4 DRAM for ISR 4431

KCS-SP421/16G

MEDIUM
DDR4 DRAM2133MHz16GBDDR4 DIMM

Crucial 16GB DDR4 DIMM for Cisco

CT16G4RFD8213

MEDIUM
DDR4 DRAM2133MHz16GBDDR4 DIMM

Kingston 8GB DDR4 DRAM for ISR 4351

KCS-SP421/8G

MEDIUM
DDR4 DRAM2133MHz8GBDDR4 DIMM

SanDisk 8GB Flash for ISR 4431

SDCF-008G-ISR

MEDIUM
Flash0MHz8GBCompactFlash

Frequently Asked Questions

What RAM fits the Cisco ISR 4431 (ISR4431/K9)?

Based on our compatibility data, the Cisco ISR 4431 (ISR4431/K9) supports DDR4 DRAM, M.2 SATA, 2133MHz, up to 16GB max, 1 slot. Matched modules include Cisco 200GB SSD for ISR 4431 (SSD, M.2 SATA, 0MHz, 200GB); Cisco 32GB Flash Memory for ISR 4400 (Flash, CompactFlash, 0MHz, 32GB); Cisco 16GB DDR4 DRAM for ISR 4431 (DDR4 DRAM, DDR4 DIMM, 2133MHz, 16GB); Cisco 8GB DDR4 DRAM for ISR 4431 (DDR4 DRAM, DDR4 DIMM, 2133MHz, 8GB); Cisco 8GB Flash for ISR 4431 (Flash, CompactFlash, 0MHz, 8GB); Kingston 16GB DDR4 DRAM for ISR 4431 (DDR4 DRAM, DDR4 DIMM, 2133MHz, 16GB); Crucial 16GB DDR4 DIMM for Cisco (DDR4 DRAM, DDR4 DIMM, 2133MHz, 16GB); Kingston 8GB DDR4 DRAM for ISR 4351 (DDR4 DRAM, DDR4 DIMM, 2133MHz, 8GB); Crucial 8GB DDR4 DIMM for Cisco (DDR4 DRAM, DDR4 DIMM, 2133MHz, 8GB); SanDisk 8GB Flash for ISR 4431 (Flash, CompactFlash, 0MHz, 8GB). Always confirm your exact model number before purchasing.

How do I verify RAM compatibility?

Check that your device label or manual shows ISR4431/K9 (or ISR 4431). Confirm memory generation, form factor (M.2 SATA), speed, slot count, and maximum supported capacity match the specs on this page before ordering.

Can I mix RAM speeds or capacities?

This device has a single RAM slot, so you typically replace the existing module rather than adding a second stick. Match the supported generation, form factor, and maximum module capacity.

Are these listings live and current?

Current eBay listings for compatible RAM modules are shown below. Prices and availability change frequently — verify listing details and seller ratings before you buy.

RAM Upgrade Guide for the Cisco ISR 4431

This device uses DDR4 DRAM at 2133MHz. Maximum supported capacity is 16GB.

This model has a single RAM slot. Maximum capacity is 16GB.

Always power off and unplug your device before installing RAM. Ground yourself to avoid static discharge.