Cisco Catalyst 3850 Switches Support Ended in 2025.

Next Step: Risks, Replacements & Cashback Options.

The Cisco Catalyst 3850 series has been essential for enterprise campus networks in the UK for nearly a decade. However, Cisco has announced that most models will reach their End of Support (EOSL) on 31 October 2025.

After this date, organisations that continue to use Catalyst 3850 switches will face higher security risks, decreased reliability, and possible compliance issues.

At Flux IT Hardware, we assist organisations at every step of Cisco’s hardware lifecycle, from EOSL planning and third-party maintenance to hardware replacement and IT equipment cashback.

Related guide: What Cisco EOSL Means for Your Network in 2026

What Does End-of-Support Mean for the Catalyst 3850?

When a Cisco switch reaches End of Support, Cisco will stop providing:

❌ Security vulnerability patches

❌ IOS XE bug fixes or software updates

❌ SmartNet hardware replacement

❌ TAC technical support

For industries such as finance, education, healthcare, manufacturing, and the public sector, using unsupported network infrastructure can also pose audit and regulatory risks.

Cisco C3850 Lifecycle

End of Sale and End of Life for the Cisco Catalyst 3850 Copper Switches

• End of Life: October 31, 2019
• End of Sale: October 30, 2020
• End of SW Maintenance Release: October 30, 2021
• End of Vulnerability/Security Support: October 31, 2025
• Last Day of Support: October 31, 2025

End of Sale and End of Life for the Cisco Catalyst 3850 Fibre Switches

• End of Life: April 30, 2021
• End of Sale: April 30, 2022
• End of SW Maintenance Release: April 30, 2023
• End of Vulnerability/Security Support: April 30, 2027
• Last Day of Support: April 30, 2027

If you’re unsure which Catalyst 3850 models are installed across your estate, Flux IT can help perform a hardware audit and lifecycle assessment.

Cisco Catalyst 3850 Replacement Options

ℹ️ Did you know? Backward compatibility with many of the C3850’s power supplies and uplink modules is a major benefit of switching from the C3850 series to the most recent Cisco Catalyst 9300 series. Because of this compatibility, users can save a lot of money by upgrading to a C9300 switch and reusing existing parts from their C3850. The compatible parts between the two-switch series are listed in the table below. Users may find the transition easier and have fewer reservations about embracing the newer technology thanks to this compatibility.

Other Benefits of Upgrading:

• Publicly available software downloads.
• Increased performance, enhanced security, and the latest software upgrades from the OEM.
• Current Gen C9300 – no EOL dates announced yet.

Risks of Running Catalyst 3850 Switches After 2025

⚠️ No security updates

⚠️ Increased risk of cyber-attacks

⚠️ No OEM support during outages

⚠️ Compliance and audit failures

⚠️ High emergency replacement costs

Having a planned lifecycle strategy is always cheaper and safer than responding to a failure.

Why Flux IT Hardware?

✔ Cisco specialists (enterprise & data centre)

✔ Large UK & EU stockholding

✔ TPM, resale, buy-back & recycling under one roof

✔ Fast response for EOSL-driven projects

✔ Sustainability-focused IT lifecycle management

We work within or outside the traditional Cisco channel, depending on what fits your organisation best.