Hi,

Page 323 explains Mac based authentication, which is what would be used if multiple devices connect to one port. https://downloads.dell.com/manuals/all-products/esuprt_ser_stor_net/esuprt_networking/esuprt_net_fxd_prt_swtchs/networking-n1500-series_administrator-guide10_en-us.pdf

Ok i know now but i don't know wchich port state choose for 1 computer connected to the port for radius authentication to login to domain. Ewen if 1 computer is connected to switch port is it ok to set mac-based port for him?

Yes you can use mac based for one computer.