CoA request fails in FreeRadius

I'm using freeradius 3.0.8. I have the following configuration in the authenticate section of sites-enabled/default

Auth-Type PAP {
       pap
          if("%{sql:SELECT radcheck.authstep FROM `radcheck` WHERE radcheck.username = '%{User-Name}' }" == 2){
           update coa {
              User-Name = "%{User-Name}"
              Packet-Dst-IP-Address = "72.23.170.105"
          }
         }
}

In radius debug log I can see it's trying to send the coa request but fails with the following warning.

(1) WARNING: Unknown destination 72.23.170.105:3799 for CoA request

However when I tried the same using radclient it worked.

echo "User-Name=EC-78-5F-DF-8A-C8" | radclient 72.23.170.105:3799 coa testing123

Only difference is I'm sending client secret with radclient command. I have already added this configuration to clients.conf

client 72.23.170.105 {
 secret = testing123
 ipaddr = 72.23.170.105
}

I'm sure client configuration is correct since the Auth-Request from this client reach the radius.

Am I missing something here?. Is there an option to set coa secret in client.conf? Appreciate your input to resolve this.

Solution

After trial and error found the solution.

I had to add coa server configuration to clients.conf inorder to get this working.

home_server example-coa {
        type = coa
        ipaddr = 72.23.170.105
        port = 3799
        secret = testing123
        coa {
                irt = 2
                mrt = 16
                mrc = 5
                mrd = 30
        }
}

This is actually poorly documented in https://github.com/FreeRADIUS/freeradius-server/blob/master/raddb/sites-available/originate-coa