Cisco Systems XR manual Command Description, SR-8

Authentication, Authorization, and Accounting Commands on Cisco IOS XR Software

aaa authentication

Command	Description
aaa group server radius	Groups different RADIUS server hosts into distinct lists and distinct
	methods.
aaa group server tacacs+	Groups different TACACS+ server hosts into distinct lists and distinct
	methods.
login authentication	Enables AAA authentication for logins.
radius-server host	Specifies a RADIUS host.
tacacs-server host	Specifies a TACACS+ host.

Cisco IOS XR System Security Command Reference

SR-8