WAN interface resets to 0.0.0.0 when cable modem reboots



  • Hi,

    I have a problem where every time my Arris cable modem reboots, the WAN interface resets to a 0.0.0.0 IPv4 address. At this point, I always have to reboot the Netgate pfSense router. I've fiddled a little bit with DHCP timeouts, but to no avail. Any pointers / tips?

    Thanks!

    -- Leif



  • It has nothing to do with timeouts. The DHCP client owns the address for the duration of the lease. 0.0.0.0 is used when an interface does not know it's address. So, when the modem reboots, the Netgate router sees something happens, but perhaps not a full shutdown. If you disconnect the Ethernet cable and reconnect, does the route get an address? You can also run Packet Capture or Wireshark to see what's happening.



  • Yeh, unplugging the WAN cable on the pfSense router does let it restore the DHCP address from upstream. That's rather annoying though, is there anyway to avoid this?

    Fwiw, after rebooting the cable modem, I see this in the log file:

    ([2.4.3-RELEASE][admin@yggdrasil.ogre.com]/var/log: tail gateways.log
    Jul 2 11:38:17 yggdrasil dpinger: WAN_DHCP 73.217.8.1: sendto error: 65
    Jul 2 11:38:18 yggdrasil dpinger: WAN_DHCP 73.217.8.1: sendto error: 65
    Jul 2 11:38:18 yggdrasil dpinger: WAN_DHCP 73.217.8.1: sendto error: 65
    Jul 2 11:38:19 yggdrasil dpinger: WAN_DHCP 73.217.8.1: sendto error: 65
    Jul 2 11:38:19 yggdrasil dpinger: WAN_DHCP 73.217.8.1: sendto error: 65
    Jul 2 11:38:20 yggdrasil dpinger: WAN_DHCP 73.217.8.1: sendto error: 65
    Jul 2 11:38:20 yggdrasil dpinger: WAN_DHCP 73.217.8.1: sendto error: 65
    Jul 2 11:38:21 yggdrasil dpinger: WAN_DHCP 73.217.8.1: sendto error: 65
    Jul 2 11:38:21 yggdrasil dpinger: WAN_DHCP 73.217.8.1: sendto error: 65)

    [2.4.3-RELEASE][admin@yggdrasil.ogre.com]/var/log: tail dhcpd.log
    Jul 2 11:37:56 yggdrasil dhclient[70868]: DHCPREQUEST on igb0 to 255.255.255.255 port 67
    Jul 2 11:37:58 yggdrasil dhclient[70868]: DHCPREQUEST on igb0 to 255.255.255.255 port 67
    Jul 2 11:38:03 yggdrasil dhclient[70868]: DHCPDISCOVER on igb0 to 255.255.255.255 port 67 interval 1
    Jul 2 11:38:04 yggdrasil dhclient[70868]: DHCPDISCOVER on igb0 to 255.255.255.255 port 67 interval 1
    Jul 2 11:38:05 yggdrasil dhclient[70868]: DHCPDISCOVER on igb0 to 255.255.255.255 port 67 interval 2
    Jul 2 11:38:07 yggdrasil dhclient[70868]: DHCPDISCOVER on igb0 to 255.255.255.255 port 67 interval 2
    Jul 2 11:38:09 yggdrasil dhclient[70868]: DHCPDISCOVER on igb0 to 255.255.255.255 port 67 interval 3
    Jul 2 11:38:12 yggdrasil dhclient[70868]: DHCPDISCOVER on igb0 to 255.255.255.255 port 67 interval 8
    Jul 2 11:38:20 yggdrasil dhclient[70868]: DHCPDISCOVER on igb0 to 255.255.255.255 port 67 interval 11



  • Given that disconnecting/reconnecting the cable works OK, the problem is likely within the modem. I seem to recall someone else had this problem not too long ago.



  • Alright, thanks for the help! Hopefully the modem won't reboot all that often :-).



  • @zwoop said in WAN interface resets to 0.0.0.0 when cable modem reboots:

    Alright, thanks for the help! Hopefully the modem won't reboot all that often :-).

    In the mean time, when it fails try just disconnecting/reconnecting the Ethernet cable.



  • @zwoop said in WAN interface resets to 0.0.0.0 when cable modem reboots:

    Alright, thanks for the help! Hopefully the modem won't reboot all that often :-).

    Modem rebooting all by itself, that is not normal.



  • @sammywoo No, but it happens (long power outages, service interruptions etc.). :-).



  • @zwoop I have a similar issue, the prob is, pfsense boots and asks for the WAN IP before my cable modem has completed its handshake with the ISP, then pfsense just sits there having failed to obtain its WAN IP. There is a post about introducing a delay boot but it doesn't seems to work reliably. It hasn't bothered me enough to spend more time on this issue thanks to my UPS.