We have a setup for l2tp ADSL and other connections using freeradius. 

All is generally working fine - I am building some coa  functionality.

The good news is that this in general works fine - I have however one problem and while I can see hints on the list and on the freeradius site I would appreciate some clarification.

We have currently 2 LNS Servers. Sessions to us can end up on either one of our LNS Servers. However I can't easily say which of the LNS devices to send the request to - the NAS IP we hold in radact is actually the Wholesale providers NAS IP not the LNS IP address.

What I would ideally like to do (simple solution) is send the coa request to both LNS routers - one will obviously say 'no match' the other will correctly affect the session. With the pool set to failover I find that second LNS is not sent the coa as the first LNS replied (albeit saying no match), load balance works 50/50.

Is there a simple way to configure coa to send the request to both here. I'm also open to any betrter routes to do this

coa config is currently

---
listen {
        type = coa
        ipaddr = *
        port = 3799
        server = coa
}

server coa {
        recv-coa {
                update control {
                        Home-Server-Pool := firebrick_pool
                }
                ok
        }
        send-coa {
                ok
        }
}
---

proxy.conf is currently:

---
home_server firebrick-1 {
        type = coa
        ipaddr = 2.3.4.5
        port = 3799
        secret = password
        require_message_authenticator = no
        response_window = 20
        zombie_period = 40
        revive_interval = 120
        status_check = none
        check_interval = 30
        num_answers_to_alive = 3
        coa {
                irt = 2
                mrt = 16
                mrc = 5
                mrd = 30
        }
}

home_server firebrick-2 {
        type = coa
        ipaddr = 1.2.3.4
        port = 3799
        secret = password
        require_message_authenticator = no
        response_window = 20
        zombie_period = 40
        revive_interval = 120
        status_check = none
        check_interval = 30
        num_answers_to_alive = 3
        coa {
                irt = 2
                mrt = 16
                mrc = 5
                mrd = 30
        }
}

home_server_pool firebrick_pool {
        type = load-balance
        home_server = firebrick-1
        home_server = firebrick-2
}
---

Any pointers would be gratefully received
 
-- 
Richard Palmer