WAN DHCP Does Not Work



  • I've spent a good 8 hours on trying to get WAN DHCP on pfSense to work, including reading through forum entries and posts all over the web, but I can't get it to work. pfSense simply doesn't acquire the WAN IP. Super frustrating. Hopefully you guys can help.

    The situation:

    • I have a dedicated Atom D525 SuperServer which is running a fresh install of pfSense 1.2.3-RELEASE.

    • My internet connection is a DHCP Comcast cable connection through a Scientific Atlanta 2100 DSL modem.

    • WAN is connected to em0 and set to DHCP, LAN is connected to em1 and set to 172.16.10.10.

    The problem:

    • The pfSense box shows WAN and LAN links up, but no WAN IP address. I can't ping or resolve anything (tried through console and LAN connected PCs).

    • Acquiring a DHCP IP works perfectly fine if I do it through my old D-Link DIR-625 router. It does not work when I connect the cable to em0 on my pfSense box.

    • As soon as I plug in my old DIR-625 router (some times I have to powercycle), the router has no problem getting an IP.

    Things I tried to remedy the problem:

    • I've allowed all WAN and LAN traffic to/from all interfaces on all protocols and ports.

    • I've cloned the MAC address of the previous DIR-625 router to the pfSense WAN interface.

    • I've powercycled the modem before unplugging, before replugging, in between.

    • I've rebooted the pfSense box, with unplugged modem and plugged modem.

    • I've logged all WAN interface traffic. Before I created the Allow-All rule, I got log entries such as "Rule 30/0(match): block in on em0: 10.250.96.1.67 > 255.255.255.255.68: BOOTP/DHCP, Reply, length 300". After creating the Allow-All rule with log flag I get the same entries with pass instead of block. This has not made a difference - still no WAN IP.

    • I've disabled the standard rule to block Private Networks and Bogon Networks on the WAN interface.

    I hope you guys can help me with this. It's driving me nuts.

    Thanks!
    subar



  • Have you checked that the network card is ok?  Have you tried a different network cable in case the cable is faulty?

    Did you remember to power the cable modem off before you connected the pfSense host?



  • @Cry:

    Did you remember to power the cable modem off before you connected the pfSense host?

    If I recall correctly, I have seen reports that it is necessary to power of the cable modem for sufficiently long for power supply capacitors to drain and force a cold restart. A momentary power dip may not be sufficient.

    @subar:

    My internet connection is a DHCP Comcast cable connection through a Scientific Atlanta 2100 DSL modem.

    Did you mean "cable modem" rather than "DSL modem"?

    Have you looked in the system logs for traces of dhclient activity (see web GUI Status -> System logs? (dhclient is the application that talks to a DHCP server to get configuration information.) Here's an example of a dhclient report on my WAN interface

    Dec 27 06:09:24 	dhclient[4423]: connection closed
    Dec 27 06:09:24 	dhclient[4423]: connection closed
    Dec 27 06:09:24 	dhclient[4423]: exiting.
    Dec 27 06:09:24 	dhclient[4423]: exiting.
    Dec 27 06:09:24 	dhclient[10226]: DHCPREQUEST on udav0 to 255.255.255.255 port 67
    Dec 27 06:09:25 	dhclient[10226]: DHCPREQUEST on udav0 to 255.255.255.255 port 67
    Dec 27 06:09:25 	dhclient[10226]: DHCPACK from 192.168.37.21
    Dec 27 06:09:26 	dhclient[10226]: bound to 192.x.y.z -- renewal in 129600 seconds.
    

    I think I've seen reports that in some (as yet ill defined) circumstances dhclient in pfSense 1.2.3 exits and doesn't restart, leaving the system with nothing actively requesting DHCP configuration so none is provided.


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