Loosing internet connection daily



  • Hello All!

    I am stumped. I think the issue is with Spectrum, but they continue to say their modem is online and working fine.

    here is what happens:

    Almost every day we 'lose' internet
    meaning I cannot connect to any FQDN but can ping and to to any site by the IP address.

    I have to manually shut down the Spectrum modem (this has been replaced 3x in past 2 months), let it sit for a min or two and plug back in. Then we get web access.

    The gateway log shows:
    Jul 28 15:09:15 LAB1pfSense dpinger: WAN_DHCP 75.183.240.1: sendto error: 65

    and
    LAB1pfSense dpinger: send_interval 500ms loss_interval 2000ms time_period 60000ms report_interval 0ms data_len 1 alert_interval 1000ms latency_alarm 500ms loss_alarm 20% dest_addr 75.183.240.1 bind_addr 75.183.241.220 identifier "WAN_DHCP "
    Jul 28 19:36:24 LAB1pfSense dpinger: send_interval 500ms loss_interval 2000ms time_period 60000ms report_interval 0ms data_len 1 alert_interval 1000ms latency_alarm 500ms loss_alarm 20% dest_addr 192.168.100.1 bind_addr 192.168.100.10 identifier "WAN_DHCP "
    Jul 28 19:36:24 LAB1pfSense dpinger: send_interval 500ms loss_interval 2000ms time_period 60000ms report_interval 0ms data_len 1 alert_interval 1000ms latency_alarm 500ms loss_alarm 20% dest_addr 192.168.100.1 bind_addr 192.168.100.10 identifier "WAN_DHCP "

    over and over. I have had this issue with my edgerouter X, a TP-link 'staples' router, and my PfSense box (SG4860 and PCengines) running latest build.

    Spectrum cites sporatic line noise which may contribute to the disconnect, but they cannot understand the errors.

    I do not have a local network of 192.168.100.1. I think the 75.183.240.1 address is a spectrum gateway but they will not comment on this.

    Is there anything I can look at to prove it is not my PfSense box?
    This same box runs fine in two other locations bu just plugging in and having the WAN as DHCP

    This location, well, we lose ability to connect to any site after a few hours

    I have clumps of hair on the floor around me as I ponder anything I can do to fix. I believe at this time it is their network outside the modem.

    Any comments are greatly appreciated.

    Thanks



  • Is the modem getting hot for any reason?



  • @detox said in Loosing internet connection daily:

    I do not have a local network of 192.168.100.1. I think the 75.183.240.1 address is a spectrum gateway but they will not comment on this.

    The DHCP client running on the pfSense WAN interface emits an DHCPDISCOVER, which is "modulated" by the modem and send to the ISP's DHCP server.

    Or, the (your) modem has also a DHCP server integrated, that hands out a RFC1918 = the IP 192.168.100.x if the upstream ISP DHCP isn't available, most probably because the link is down. This is useful, as it permits you to access the modem's GUI, to set it up.

    Normally, when the pfSense WAN interface comes up, and you use the DHCP cient on it, it should start asking for IP/mask/gateway right away. The connection should go up ASAP.
    But ..... modem tend to be slow to sync with the link's carrier.

    Start by checking this option

    f01b81b2-2f64-4c1c-aafc-21af4995eab3-image.png

    Now you have extra option.
    Like : do not accept IP's from the 192.168.100.0 network
    or
    When the WAN comes up, back-off some xx seconds, so the modem has time to prepare the link to the ISP, so a first DHCPDISCOVER from pfSense will be reaching the ISP DHCP server, and pfSense will receive a 'real' WAN IP and gateway.

    See also the pfSense manual for more details.



  • Gertjan,

    Thank you for your assistance. I have found some material that I think you are referring to on:

    https://www.freebsd.org/cgi/man.cgi?query=dhclient.conf&sektion=5#PROTOCOL_TIMING

    Here are the two areas I think you are speaking of:

    backoff-cutoff time;
         The client	uses an	exponential backoff algorithm with some	ran-
         domness, so that if many clients try to configure themselves at
         the same time, they will not make their requests in lockstep.
         The backoff-cutoff	statement determines the maximum amount	of
         time that the client is allowed to	back off.  It defaults to two
         minutes.
    
     initial-interval time;
         The initial-interval statement sets the amount of time between
         the first attempt to reach	a server and the second	attempt	to
         reach a server.  Each time	a message is sent, the interval	be-
         tween messages is incremented by twice the	current	interval mul-
         tiplied by	a random number	between	zero and one.  If it is
         greater than the backoff-cutoff amount, it	is set to that amount.
         It	defaults to ten	seconds
    

    I am not sure which is correct. Also, how many seconds do you recommend to back-off the first dhcpdiscover?

    With this fix in mind would it be better to get a static IP from Spectrum? That way I would not need to fiddle with timing issues?

    Again, thank you so much!



  • @detox said in Loosing internet connection daily:

    to get a static IP from Spectrum? That way I would not need to fiddle with timing issues?

    Thing about this : the actual source of the issue is the LAN port of the modem going down, to signal the downstream device = pfSense that the "WAN" connection changed. Probably because the 'uplink' went down for a planned / non planned reason.
    Static, or not, the uplink has to be constructed again. If the IP on pfSense was static, you would have another process taking it's time to "test and reset if not ok" the WAN interface : dpinger.
    dpinger is responsible for testing the upstream gateway by sending a ping every x seconds, or any other IP at your choice, so pfSense knows if a WAN is operational.

    So, keep it simple, use the backoff-cutoff time, set it to 2 minutes, reset de modemn, see if you obtained a good WAN IP, then lower the backoff-cutoff time with 10 seconds, reset again.
    As soon as you get a RFC1918 IP, you know that you have to add back 10 seconds, and an extra 10 seconds margin, and you'll be ok.



  • @detox said in Loosing internet connection daily:

    meaning I cannot connect to any FQDN but can ping and to to any site by the IP address.

    What model modem?



  • @Gertjan ,

    If I may ask for a bit of clarification.....

    I spoke with Spectrum (internet provider).
    They stated their newer modems (at least the pass-through ones) handle signal / power disruptions as such:

    Whenever the modem loses signal/ power, in order to regain internet these steps must be done:
    Unplug power from modem and router
    after 60 sec plug power back to modem
    once modem is solidly connected (as shown by diag lights)
    plug power back to router.

    Only this way will connectivity be reestablished.

    So, back to the backoff-cutoff switch

    I am assuming it is measured in seconds, so to determine the correct time as you suggested, unplug then reconnect power to modem with PfSense attached.

    Begin counting until it reflects a WAN IP.
    Then add 10 seconds and enter this amount into the backoff-cuttoff switch. (to start)

    Am I understanding this?

    Thank you for your patience in this.



  • @detox said in Loosing internet connection daily:

    Almost every day we 'lose' internet
    meaning I cannot connect to any FQDN but can ping and to to any site by the IP address.

    This sounds like a DNS thing. What are your DNS settings? Are you using DNS Resolver, DNS Forwarder, DNS Resolver in forwarding mode? If so, what DNS servers do you have under System > General Setup page.


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