Thank you Alan Buxey. Here are my debug result: radtest jzwang@yyy.yyy.yy 'yyy11111' localhost 18120 testing123 Sending Access-Request of id 149 to 127.0.0.1 port 1812 User-Name = "jzwang@yyy.yyy.yy" User-Password = "yyy11111" NAS-IP-Address = 10.10.10.10 NAS-Port = 18120 Message-Authenticator = 0x00000000000000000000000000000000 Sending Access-Request of id 149 to 127.0.0.1 port 1812 User-Name = "jzwang@yyy.yyy.yy" User-Password = "yyy11111" NAS-IP-Address = 10.10.10.10 NAS-Port = 18120 Message-Authenticator = 0x00000000000000000000000000000000 Sending Access-Request of id 149 to 127.0.0.1 port 1812 User-Name = "jzwang@yyy.yyy.yy" User-Password = "yyy11111" NAS-IP-Address = 10.10.10.10 NAS-Port = 18120 Message-Authenticator = 0x00000000000000000000000000000000 radclient: no response from server for ID 149 socket 3 Ready to process requests. rad_recv: Access-Request packet from host 127.0.0.1 port 56584, id=149, length=8 9 User-Name = "jzwang@yyy.yyy.yy" User-Password = "yyy11111" NAS-IP-Address = 10.10.10.10 NAS-Port = 18120 Message-Authenticator = 0x40bb61c5f9140c89eceab51ae14f3df3 # Executing section authorize from file /etc/freeradius/sites-enabled/default +- entering group authorize {...} ++[preprocess] returns ok ++[chap] returns noop ++[mschap] returns noop ++[digest] returns noop [suffix] Looking up realm "yyy.yyy.yy" for User-Name = "jzwang@yyy.yyy.yy" [suffix] No such realm "yyy.yyy.yy" ++[suffix] returns noop [eap] No EAP-Message, not doing EAP ++[eap] returns noop [files] users: Matched entry DEFAULT at line 73 ++[files] returns ok ++[expiration] returns noop ++[logintime] returns noop [pap] WARNING! No "known good" password found for the user. Authentication may fail because of this. ++[pap] returns noop Found Auth-Type = PAM # Executing group from file /etc/freeradius/sites-enabled/default +- entering group authenticate {...} pam_pass: using pamauth string <radiusd> for pam.conf lookup pam_pass: authentication succeeded for <jzwang@yyy.yyy.yy> ++[pam] returns ok Login OK: [jzwang@yyy.yyy.yy/yyy11111] (from client localhost port 18120) # Executing section post-auth from file /etc/freeradius/sites-enabled/default +- entering group post-auth {...} ++[exec] returns noop Sending Access-Accept of id 149 to 127.0.0.1 port 56584 Finished request 0. Going to the next request Waking up in 4.9 seconds. rad_recv: Access-Request packet from host 127.0.0.1 port 56584, id=149, length=89 Sending duplicate reply to client localhost port 56584 - ID: 149 Sending Access-Accept of id 149 to 127.0.0.1 port 56584 Waking up in 4.9 seconds. rad_recv: Access-Request packet from host 127.0.0.1 port 56584, id=149, length=89 Sending duplicate reply to client localhost port 56584 - ID: 149 Sending Access-Accept of id 149 to 127.0.0.1 port 56584 Waking up in 4.9 seconds. Cleaning up request 0 ID 149 with timestamp +164 Ready to process requests.