[server:~] # pkg_add -r freeradius

[server:~] # cat /etc/rc.conf
...
radiusd_enable=yes
...

[server:~] # cd /usr/local/etc/raddb/

root@server:~# apt-get install freeradius

root@server:~# cd /etc/freeradius/

server# cat sites-available/default

...
#     unix
...
#     unix
...

server# cat users

user1 Cleartext-Password := "rpassword1"

user2 Cleartext-Password := "rpassword2"

server# cat clients.conf

...
client gate.corpX.un {
        secret          = testing123
        shortname       = gate
}
...

[server:~] # /usr/local/etc/rc.d/radiusd start

root@server:~# /etc/init.d/freeradius restart

[gate:~] # cat /etc/radius.conf
auth server testing123 3 2

[gate:~] # cat /etc/pam.d/login
...
auth            sufficient      pam_radius.so           no_warn try_first_pass
auth            include         system             
...

root@gate:~# apt-get install libpam-radius-auth freeradius-utils

root@gate:~# cat /etc/pam_radius_auth.conf
...
server testing123 3
...

root@gate:~# cat /etc/pam.d/login
...
auth       sufficient   pam_radius_auth.so
# Standard Un*x authentication.
...