/etc/freeradius/3.0/users

tech Cleartext-Password := "password"
        Service-Type = Administrative-User,
        cisco-avpair = "shell:priv-lvl=10"

$enab15$  Cleartext-Password := "class123"
        Service-Type = Administrative-User,
        cisco-avpair = "shell:priv-lvl=15"

===================================
/etc/freeradius/3.0/clients.conf

client 10.10.10.1 {
  secret = cisco123
  shortname = ESR1
}