Outbound load balancer - DHCP Wan gateway never come back to online.



  • Here is a more detailed report of the problems i got after a load balancer failover :

    My setup use linksys AM200 ADSL modems in half bridge mode (modem is managing PPP, and deliver a public IP to PFsense through DHCP) :

    case 1 : the modem ADSL phone line is disconnected : no problem here, Pfsense detect the failure and switch to another Gateway. After line reconnection, Pfsense detect the modem liveness and come back to this Gateway.

    case 2 : the modem Ethernet plug is disconnected, simulating a modem connection problem : Pfsense detect the failure and switch to another Gateway. After Ethernet plug reconnection, Pfsense does not detect the modem liveness and never come back to this Gateway.

    To get this gateway detected again correctly as Online, i need to release and renew the interface.

    case 3 : same as before but powering off the modem, simulating a modem outage. Pfsense has the same reaction as case number 2. it doesn't detect this interface as Online after modem power on. Again, i need to release and renew the interface.

    I do not know exactly why connectivity is lost for case 2 and 3. Perhaps it is because the modem need to see a DHCP request before to effectively deliver trafic again. This would explain why an interface realease / renew does solve the problem.

    Perhaps PFsense should force a DHCP renew when a link down / link up is detected, and perhaps as well force a renew at periodic intervals  during a ping connectivity failure.

    I can test as well PPPOE and static mode if needed.


Log in to reply