When navigating in Mist from Clients > Wired Clients, the information listed in that grid is way larger than the mac and arp tables of the core switch.

Mist seems to know about more clients than the core device.

Mist Wired Clients grid is a powerful view, and it is built by correlating multiple data sources from all the switches living in a site. E.g it considers:

- MAC / CAM tables.

- DHCP snooping database / ARP inspection.

- LLDP / LLDP-MED.

- User/device, if applicable from 802.1X.

A Core switch on the other hand, will fill up its tables by learning data from its own locally ran protocols and from the traffic that traverses its links, it will also eventually start to flush the entries if the hosts stop communicating with each other, so the information is way more limited.