The Definitive Guide to Cat3K: Cisco Catalyst 3850 Series Networking
The Cisco Catalyst 3750-X and 3560-X are not modern switches. They lack mGig, they can't run VXLAN, and they consume twice the power of a modern equivalent. The Definitive Guide to Cat3K: Cisco Catalyst 3850
These switches run Cisco IOS Classic (15.0 to 15.2). For veterans, this is a blessing. No complicated IOS-XE guest shells, no Python scripts required, no mandatory smart licensing headaches (though Smart Licensing was introduced late in the lifecycle). For veterans, this is a blessing
This meant a switch bought in 2010 could still support 10G uplinks in 2018 without a forklift upgrade. That kind of investment protection is unheard of today. That kind of investment protection is unheard of today
Furthermore, Cisco announced for the 3750-X/3560-X on October 31, 2022 . While they still run, you cannot get security patches or TAC support. Consequently, the secondary market is flooded with them for $50–$200—a steal for homelabs, but a liability for regulated industries (HIPAA, PCI).
While the newer Catalyst 9000 series represents the future of the portfolio, legacy Cat3k platforms (such as the 3850 and 3650) are approaching or have reached End of Sale (EOS) and End of Life (EOL). This report recommends a strategic migration path toward the Catalyst 9000 series to ensure continued support, security updates, and network programmability.