Cisco C1-CISCO4431/K9 Cisco ONE ISR 4431 Branch Router

C1-CISCO4431/K9 Exact Cisco ONE Identity

C1-CISCO4431/K9 is Cisco's former Cisco ONE hardware PID for the ISR 4431. Cisco's affected-product table identifies four onboard GE ports, three NIM slots, 8 GB flash, 4 GB DRAM and IP Base. The C1 prefix describes the retired Cisco ONE order line; it must not be silently replaced with a current subscription claim.

4431 capacity and expansion case

The ISR 4431 platform has more onboard GE and NIM capacity than the C1-CISCO4331/K9 order line. Cisco's family data sheet lists 500 Mbps default aggregate throughput and 1 Gbps with the performance license for ISR 4431, with higher CEF-only boost behavior documented separately. Verify the installed license and measured service mix before using any licensed throughput figure in a design.

Module and software inventory

Record every NIM, interface, power supply, memory item, IOS XE image and active entitlement. Confirm that each module is supported by the target software release and that required encryption, routing, voice or SD-WAN functions are licensed. The base Cisco ONE PID alone does not establish which later software rights remain transferable.

Lifecycle boundary

Cisco ended sale of this exact Select Cisco ONE hardware order line on October 28, 2022 and lists October 31, 2027 as its last support date. Cisco named ISR4431/K9 as the replacement order line. The underlying ISR 4431 platform has a separate support record, so procurement must evaluate both the exact PID lifecycle and the installed chassis/service status.

Migration acceptance

For continued operation, retain configuration backups, serial and entitlement evidence, WAN media, module compatibility and performance measurements. A migration plan should map interfaces, routing, security, application hosting and failover to a currently supported Cisco edge platform rather than assuming a configuration can be copied unchanged.

Official sources: Cisco Select Cisco ONE hardware lifecycle and exact PID table, Cisco ISR 4000 family data sheet and Cisco ISR 4431 support record.