Cisco 4000 Series ISR EOL: Dates by Model & Migration (2026)

The Cisco 4000 Series ISR is end of sale. Cisco’s official series page (checked October 2026) gives these dates:

• ISR 4221, 4321, 4331, 4351, 4431, 4451-X: Last Date of Support is 30 November 2028.
• ISR 4461: end of sale was 20 January 2025. Last Date of Support is 31 January 2030.
• Recommended replacement: Cisco Catalyst 8000 Edge Platforms (8200 and 8300).

The routers keep running after these dates. What ends is Cisco’s TAC support, RMA and software remedies. In practice the 2028 and 2030 dates matter less than the earlier cut-offs for contract renewal, software maintenance and spare parts. Those are covered below.

Cisco 4000 Series ISR EOL dates by model

*Per EOL14896 (ISR4200, ISR4300 and select ISR4400 platform). Confirm your exact PID in the bulletin’s part-number table.

The series was released on 16 September 2014. Cisco’s page shows the series-level End-of-Sale as 20 Jan 2025 (the 4461, the last model sold) and the series-level End-of-Support as 31 Jan 2030.

ISR 4461 lifecycle in detail

The 4461 has the longest runway. Its milestones, from bulletin EOL15446:

Two dates are easy to miss:

1. From 20 Jan 2026 you can’t add a new 4461 to a service contract. A used 4461 with no contract can’t be brought under support.
2. Contracts can only be renewed until 17 Apr 2029, about nine months before the Last Date of Support.

Cisco also publishes separate EoL notices for individual IOS XE trains (for example 17.9.x, 17.12.x, 17.15.x, 17.16.x and 17.17.x). A router can therefore be supported while the software train it runs is not. Check your train as well as your hardware.

What the milestones mean

• End-of-Sale: the product can no longer be ordered through Cisco.
• End of SW Maintenance Releases: Cisco stops developing and fixing the software. Security fixes can continue for a defined period after this.
• End of Service Contract Renewal: the last day you can extend a contract.
• Last Date of Support: TAC, RMA and remedies end, and the product becomes obsolete.

Spare parts ended earlier. Spares for the ISR4200, ISR4300 and select ISR4400 (rack-mount kits, bezels and similar) had a last order date of 26 January 2024 (EOL15205). Individual items such as the 4 GB DRAM for the ISR 4300 and the CAT 6 NIMs have their own EoL notices.

Known issues and field notices

The official support page lists these notices. Check whether they apply to your fleet:

• FN64253: ISR4331, ISR4321, ISR4351 and UCS-E120 might fail after 18 months or longer due to a clock-signal component failure (replace on failure).
• FN74073: some PWR4320 power supplies on the ISR 4321 may experience component failure.
• FN74118: some PWR-CC1-500WAC power supplies on the ISR 4431 can show incorrect power readings, causing incorrect fan control.
• FN63938: ISR4451-X and ISR4431 silent “power-on” reload, which needs a CPLD update.
• FN72510: weak cryptographic algorithms are no longer allowed by default for IPsec in certain IOS XE releases. Check this before upgrading.
• FN74350: Cisco Unified Border Element impact from TLS certificates with Client Authentication EKU (workaround provided).
• Secure Boot hardware tampering advisory (2019): Cisco published specific remediation instructions for ISR 4000.
• Snort 3 advisories (Feb–Mar 2026): these affect devices running Snort IPS.

Replacement: Catalyst 8000 Edge Platforms

Cisco’s migration path is the Catalyst 8000 family. Per Cisco’s Catalyst 8300 FAQ and ordering guide:

Modules that don’t carry over:

• NIM-1GE-CU-SFP and NIM-2GE-CU-SFP
• SM-X-ES3-16-P, SM-X-ES3-24-P and SM-X-ES3-48-P
• SM-X-6X1G and SM-X-4X1G-1X10G
• UCS-E M1/M2

Other differences:

• SFPs from the ISR 4000 work, but the 8300 doesn’t support 100 Mbps SFPs.
• Older EHWIC modules from ISR G2 aren’t supported.
• Catalyst 8000 is generally sold with a Cisco DNA subscription. Confirm the current ordering model with your partner.

Migration checklist

1. Inventory: run show inventory and show version on every router to record PID, serial, NIMs, SM-Xs and IOS XE version.
2. Contract dates: check each device’s contract end against its renewal cut-off.
3. Module mapping: compare your modules against the exception list above. Don’t map by port count alone.
4. Performance: size on real encrypted throughput and SD-WAN needs, not on interface counts.
5. Licensing: work out whether the DNA subscription model fits your budget. Check FN72510 before reusing old IPsec configs.
6. Phasing: replace sites on the 2028 models first, and plan 4461 sites for 2028–2029.

[Author’s take: replace with your own experience]

• My view is that the contract renewal cut-off is the date to plan around, not the Last Date of Support. A device that can’t be renewed is effectively unsupported 6–12 months before the official date.
• The biggest migration surprise is usually modules, not the chassis. Cisco’s compatibility list is good, but sites with FXO/FXS voice, LTE or switching modules need a per-site check.
• Use the 2–3 years left as a window to test a Catalyst 8200 or 8300 at one pilot site.
• I’d treat the 4461 as a bridge to 2029 at most, not a long-term platform.

Buying used ISR 4000

• Lab and training: the 4221 and 4321 are cheap and run modern IOS XE, so they work for CCNA/CCNP practice.
• Production: only if you accept running without TAC support.
• Check before buying:
  • The router’s licence state (Smart Licensing / RTU) and any throughput licence.
  • Which NIMs and SM-Xs are included.
  • The serial number against Cisco’s coverage tools.
  • For a 4461, remember that a new service contract can no longer be attached.
• Cold spares: chassis and spare parts are no longer orderable new. Stocking spares is reasonable if you’re in no hurry to migrate.

FAQ

Is the Cisco ISR 4000 still supported?
Yes, with an active service contract. Support runs to 30 Nov 2028 for most models and 31 Jan 2030 for the 4461.

When does ISR 4331 support end?
The Last Date of Support is 30 November 2028.

What replaces the Cisco ISR 4000?
The Catalyst 8000 Edge Platforms (8200 and 8300).

Do ISR 4000 modules work in Catalyst 8300?
Most do. There is a short exception list, shown above.

Does the router stop working after the Last Date of Support?
No. It keeps forwarding traffic, but TAC, RMA and security remedies are no longer available.

Can I still get software updates for the ISR 4461?
Routine maintenance releases ended 20 Jan 2026. Whether security fixes continue depends on Cisco’s vulnerability-support milestone, so check the bulletin.

Sources: Cisco 4000 Series ISR support page; EOL14896; EOL15205; EOL15446; Catalyst 8300 Series Edge Platforms FAQ; Catalyst 8300/8200 Ordering Guide.