Pertama pastikan squid telah terinstall dengan benar, dan dapat berjalan dengan baik, selanjutnya install FreeRADIUS yang di koneksikan ke LDAP

ldap {
                server = "ldap.xx.xx.xx"
                basedn = "ou=people,o=Universitas Gadjah Mada,dc=ugm,dc=ac,dc=id"
                filter = "(uid=%{Stripped-User-Name:-%{User-Name}})"
                start_tls = no
                dictionary_mapping = ${raddbdir}/ldap.attrmap
                ldap_connections_number = 5
                edir_account_policy_check=no
                timeout = 4
                timelimit = 3
                net_timeout = 1
                compare_check_items = no
                set_auth_type = yes
}
authorize {
                preprocess
                suffix
                ldap
}            
authenticate {
                Auth-Type LDAP {
                ldap
        }
}

Tes autentikasi ldapnya

radtest masrifqi xxxxx localhost 0 radius
Sending Access-Request of id 5 to 127.0.0.1 port 1812
	User-Name = "username"
	User-Password = "xxxxx"
	NAS-IP-Address = 255.255.255.255
	NAS-Port = 0
rad_recv: Access-Accept packet from host 127.0.0.1:1812, id=5, length=20

Install radius autentikatornya dari port saja (biar gampang) lalu install

cd /usr/ports/www/squid_radius_auth
make && make install

Kemudian pada config squid tambahkan baris berikut

auth_param basic program /usr/local/libexec/squid/squid_radius_auth -f /usr/local/etc/squid/squid_radius_auth.conf
acl ldapauth proxy_auth REQUIRED
http_access allow lan ldapauth
http_access deny all

Terakhir reload configurasi squid

/usr/local/sbin/squid -k reconfigure

Selamat mencoba :)