Portal authentication for only some end users

Hello all,

We configured DHCP on S6730S to assign IP to users. After obtaining IP addresses, users need to pass portal authentication to access the network. The portal authentication configuration is as follows: 

#

radius-server template rd1

 radius-server shared-key cipher %^%#Q75cNQ6IF(e#L4WMxP~%^7'u17,]D87GO{"[o]`D%^%#

 radius-server authentication 192.168.2.30 1812 weight 80

#

web-auth-server abc                                                             

 server-ip 192.168.2.20                                                         

 port 50200                                                                     

 shared-key cipher %^%#t:hJ@gD7<+G&,"Y}Y[VP4\foQ&og/Gg(,J4#\!gD%^%#                         

 url http://192.168.2.20:8080/webagent      

#

aaa

 authentication-scheme abc

  authentication-mode radius

 domain isp1

  authentication-scheme abc

  radius-server rd1

#

interface Vlanif10                                                              

 web-auth-server abc direct  

#

Now we hope that some specific users can access the Internet without authentication. How do I configure this? Thank you!