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Selfhosted @lemmy.world
smashing3606 @feddit.online

emergency remote access

I just wanted to see what other selfhosters backup emergency plan is if the primary internet router goes offline but the internet isn't out (ie a router reboot would fix the problem), leaving you without access to your stuff even via vpn.

the options I've considered so far:

  1. cellular smart plug to reboot router

I tried a ubibot smart plug (SP1) that is supposed to work with cellular, but the device or sim is bad. I'm currently troubleshooting. The problem with this one is it requires a proprietary cloud service, it's supposedly self hostable, but it's a pia to setup and their app port can't be changed easily allowing for a reverse proxy setup on VPS.

  1. the other option I am considering is cellular wifi router and a wifi smart plug connected to that device to reboot router

what other options have I overlooked? Also, specific models of devices would be helpful info from others doing this already.

TIA!

Edit: also just thought of possibly a cellular internet backup on my opnsense box, but from everything I've read that's also very involved to setup

Edit2: I've setup a homeassistant automation to reboot a zigbee smart plug if 2 external hosts are down for 15 mins, will try this out for a bit. I still need tp troubleshoot why the device goes down in General. Thanks for all the responses and ideas!

55 comments
  •  bash
        
0 4   *   *   *    /usr/sbin/reboot

    Adjust interval as needed.

    Or if you want something a bit faster and less disruptive: 

     bash
        
#!/bin/sh

NAME="$0"

logger_cmd () {
  echo $@
  logger -p daemon.info -t "$NAME[$$]" $@
}

if ! which ncat 1>/dev/null
then
  logger_cmd "ncat not found, installing..."
  opkg update && opkg install ncat
fi

chk_conn () {
  echo "Checking connectivity to $@"
  if ncat --send-only --recv-only -w 334ms $@ 2>/dev/null; then
    return 0
  fi

  logger_cmd "Cannot reach $@"
  return 1
}

restart_network_iface() {
    # TODO: Don't restart every minute

    COOLDOWN_LOCK=/tmp/internet-connectivity-watchcat.tmp
    COOLDOWN_SECONDS=300

    cooldown_time_end=$(cat $COOLDOWN_LOCK || echo 0)

    time_now="$(cat /proc/uptime)"
    time_now="${time_now%%.*}"

    cooldown_time_left=$((cooldown_time_end - time_now))

    if [ "$cooldown_time_left" -lt "1" ]
    then
        logger_cmd "Restarting network interface: \"$1\"."
        ifdown "$1"
        ifup "$1"

        cooldown_time_end=$((time_now + COOLDOWN_SECONDS))
        echo $cooldown_time_end > $COOLDOWN_LOCK
    else
        logger_cmd "Skipping interface \"$1\" restart due to cooldown. Cooldown left: $cooldown_time_left seconds"
    fi
}


logger_cmd "Checking internet connectivity..."

if   chk_conn google.com 443 \
  || chk_conn amazon.com 443 \
  || chk_conn facebook.com 443 \
  || chk_conn cloudflare.com 443 \
  || chk_conn telekom.de 443
then
  logger_cmd "Connected to internet."
else
  logger_cmd  "Not connected to internet."
  restart_network_iface "$1"
fi

    In restart_network_iface use /usr/sbin/reboot instead of interface up/down and run the script every few minutes via cron or systemd timer. This was written for OpenWrt so if you use that you can use it as-is. For other systems you'd also have to adjust the logger_cmd.

    You can place that on another machine and send a signal to a smart plug instead if you're worried of a locked up / frozen router. That said if your router freezes like that, you should probably change it and you should be able to run this script on it.

    • If your problem is brief brownouts or similar --- my experience is that some consumer broadband routers have cheap power supplies that leaves them in bad states when PCs will pull through --- you could put them on a UPS.
    • If your problem is that your router is unstable, you could just replace your router. Like, if you need remote access and you have a flaky router, that seems like a prime choice.
    • You could have a power control device or something and have another machine on your network set up so that if it loses Internet connectivity for some sustained period of time, it power-cycles the router.
    • If this is for when you're a long ways away, do you have a friend who you'd trust with a key and flipping a switch?
    • I expect that there are business-oriented routers that will have integrated watchdog features that will auto-reboot if they hang. I have not gone looking, though.
    • Possibly, if it's compatible with your use case, and uptime is critical enough here, having a second, backup server elsewhere, possibly not self-hosted. I mean, your connectivity is always going to be bounded by the reliability of your residential Internet connection otherwise.

  • Redundancy. I have two independent firewalls, each separately routing traffic out through two totally independent multi-homed network connections (one cable, one DSL, please god somebody give me fiber someday) that both firewalls have access to. For awhile was thinking of replacing the DSL with starlink until Elon turned out to be such a pile of nazi garbage, so for now DSL remains the backup link.

    To make things as transparent as possible, the firewalls manage their IPs with CARP. Obviously there's no way to have a single public IP that ports itself magically from one ISP to another, but on the LAN side it works great and on the WAN side it at least smooths out a lot of possible failure scenarios. Some useful discussions of this setup are here.

55 comments