DHCP for 2nd WAN i/f & modem half bridged help

  • Hi, I'm tearing my hair out trying to work around this…

    I have two WAN interfaces:

    1. WAN - ADSL2+ full bridge mode PPPOE under pfsense works great. Provider: IINET

    2. OPT2 - ADSL2+ half bridge mode using PPPOE. Interface reports identical IP address (which is my correct static IP) to that of the gateway (which is wrong, should be gateway address of the provider). Provider: TPG

    WAN2 interface (em3)
    Status up
    DHCP up 
    MAC address XX:XX:XX:XX
    IP address  XXX.XXX.XXX.124 
    Subnet mask
    Gateway XXX.XXX.XXX.124
    Media 100baseTX <full-duplex>In/out packets 108/173 (31 KB/53 KB)
    In/out errors 0/0
    Collisions 0

    Each WAN interface use a TP-LINK 8840 modem.

    Can anyone give me some clues how to debug this ?



  • just to clarify each WAN i/f has its own modem/line/provider. The first WAN i/f is working (I'm using it now) Further reading suggests that the duplicate IP and gateway information might be correct on the second WAN i/f but I am not sure.

    NAT and Firewall rules are correct. If I switch the outbound NAT from WAN (the one I am using now ) to OPT2 (second WAN which use DHCP & half bridge modem) traffic doesn't get out.

  • The subnetmask for such a configuration (IP and Gateway identical) should have a /32 subnetmask or a in other notation. If you can't get this fixed at the modem or by the ISP just set the modem to router mode and create another private subnet between the modemrouter and the pfsense. Then set the pfSense IP as DMZ IP in the modemrouter and it should work. You should of course use an external monitor IP for that link then.

  • Thanks. Could you explain why if I connect using the modem & PPPOE (bypassing pfsense) I get my static IP address and a different gateway address (as I would expect), yet when using half bridge in the modem with PPP extensions and pfsense that g/w address is not passed to pfsense via dhcp ?

    I have tried using both DHCP & static mode for the OPT2 WAN i/f.

  • It's either an issue with the modem in halfbrige mode or the ISP I think.

  • I have a similar situation.

    My WAN is doing a Full Bridged connection ADSL2+ with TPG

    My WAN2 (OPT2) is a Symetrical link static IP. If I disconnect th WAN link it brings down my WAN2 link I can't ping to any IP's on my DMZ (Routed via WAN2)

    What is going on?

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