Setup an access list on the router allowing them to communicate in the first place. If that is the 4500 set it up there.

Cisco is expanding its Catalyst family of switches for enterprises that need to blend industrial and operational technology (OT) systems The the ruggedized Catalyst Industrial Ethernet 9300 1RU ...

Fresh off its acquisition of 128 Technology, the networking giant is combining AI and SD-WAN , as well as announcing a new access switch that will compete directly with the Cisco Catalyst 9300 series, ...