'none': System-defined group, no members. All authentication requests against this group type will be automatically authorized. 'local': System-defined group, no members. All authentication requests against this group type will be locally authorized. 'radius': System-defined group, open exclusively to RADIUS server members. All authentication requests against this group type will be authorized via RADIUS based on configuration order 'tacacs': System-defined group, open exclusively to TACACS+ server members. All authentication requests against this group type will be authorized via TACACS based on configuration. order '123xyz': User-defined group, open exclusively to RADIUS or TACACS+ server members but not both. All authentication requests against this group type will be authorized based on configuration order.