ISR4431/K9 - Cisco 4000 Family Integrated Services Router

Identify the base ISR4431/K9 order

This listing is for the Cisco ISR 4431 hardware PID, rather than an AX or SEC software bundle. Four onboard Gigabit Ethernet interfaces, three Network Interface Module slots and one Integrated Services Card slot are listed. The 4431 has no SM-X service-module slots; do not select a larger ISR model's module layout for this chassis.

Check a retired platform before ordering

Cisco's amended EOL14896 notice includes this exact PID. End of sale was November 7, 2023 and general software maintenance ended August 31, 2025. The new-service attachment deadline, November 6, 2024, has passed. Contract renewal ends February 5, 2028; last support and vulnerability/security support end November 30, 2028, subject to eligible active contracts or warranty terms. A resale listing does not create a new Cisco support entitlement.

Keep firmware and forwarding rights separate

The notice identifies IOS XE 17.9.x and 17.12.x as the last supported trains; 17.10.x and 17.11.x are excluded. Record the installed release, existing coverage and migration plan. The published default aggregate forwarding tier is 500 Mbps; FL-44-PERF-K9 enables the separate 1 Gbps tier. These are licensed aggregate tiers, not a promise that each port or every enabled service forwards at that rate. Confirm the actual license inventory and workload instead of assuming the base hardware includes the upgrade.

Prepare the supplied-unit acceptance record

Capture the serial label, installed modules, power assemblies, memory configuration and license status. Separate chassis capability from what the quotation actually includes. For replacement planning, Cisco lists C8300-1N1S-4T2X and C8300-1N1S-6T; compare interfaces, modules and licensing before selecting either. The manufacturer family image is illustrative and does not document the configuration or condition of a supplied unit.

Cisco exact-PID lifecycle notice | Cisco ISR 4000 hardware and license data sheet