DHCP WAN Address Issues w/ Spectrum Cable Modem



  • I am having a strange issue with my cable modem and the WAN interface on my PFSense machine. If I have any issue with the cable modem going offline/bouncing, the PFSense box will have issues on the WAN interface and show it going up and down multiple times per minute. I can force the issue by making changes to the WAN address on PFSense. It will cause the same behavior. I have attached the logs for the DHClient showing the last 500 entries. You can see it showing multiple requests.

    Logs: removed

    @Derelict



  • @ikyo I can supply any other logs that might be needed.



  • It happened again overnight at some point. I am not sure when it happened, but the same issue. I also looked at the system.log and seeing this a lot in it:

    Nov 20 01:57:29 pfSense php-fpm[9255]: /rc.newwanip: The command '/usr/local/sbin/unbound -c /var/unbound/unbound.conf' returned exit code '1', the output was '[1542700649] unbound[25578:0] error: bind: address already in use [1542700649] unbound[25578:0] fatal error: could not open ports'

    I am not sure that would cause the interface to go up and down. Here is how fast it happens:

    Nov 20 01:57:55 pfSense kernel: bge1: link state changed to UP
    Nov 20 01:58:02 pfSense kernel: bge1: link state changed to DOWN
    Nov 20 01:58:08 pfSense kernel: bge1: link state changed to UP
    Nov 20 01:58:14 pfSense kernel: bge1: link state changed to DOWN
    Nov 20 01:58:26 pfSense kernel: bge1: link state changed to UP
    Nov 20 01:58:29 pfSense kernel: bge1: link state changed to DOWN
    Nov 20 01:58:38 pfSense kernel: bge1: link state changed to UP
    Nov 20 01:58:45 pfSense kernel: bge1: link state changed to DOWN
    Nov 20 01:58:48 pfSense kernel: bge1: link state changed to UP
    Nov 20 01:58:54 pfSense kernel: bge1: link state changed to DOWN
    Nov 20 01:59:01 pfSense kernel: bge1: link state changed to UP
    Nov 20 01:59:07 pfSense kernel: bge1: link state changed to DOWN
    Nov 20 01:59:10 pfSense kernel: bge1: link state changed to UP
    Nov 20 01:59:16 pfSense kernel: bge1: link state changed to DOWN
    Nov 20 01:59:30 pfSense kernel: bge1: link state changed to UP



  • I found a couple of posts online that had a similar issues https://forum.netgate.com/topic/76480/wan-flaps-when-cable-disconnected/18 . I am going to try changing that and see if it corrects the issue.



  • So far so good, I manually configured the interface and I think it has been fixed.