31–40 of 141 posts
Some german ISPs used to force a reset of home internet connections every 24h to trigger IP changes so that static IPs would remain reserved for the business tier. The time of the reset could be shifted by preemptively reconnecting at a desired time, they only reset the link after 24h of actual uptime.
Launch ´mtr google.com’ on one of your devices (preferably connected via Ethernet to your router) a few minutes before the cut off, and watch what happens when the cut occurs. It will show you exactly which equipment on the route starts dropping. Although I suspect your ISP has a 24h lease and your modem renegociates at 3:40 everyday
The way DHCP 'should' work is that when a client is part-way through the lease it should try to renew the IP it already has:
* https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Pro...
* https://tools.ietf.org/html/rfc2131#section-4.4.5
This allows the client to (hopefully) keep extending the IP it has so that a re-IP does not cause current connections to drop. If the modem is not doing this (can the OP log into it in someway to see logs?), then it is acting as a 'non-ideal' DHCP client.
Until this is sorted out, try rebooting the modem an an 'odd' hour that will not disrupt you during the day. This is no guarantee though: the DHCP server may remember the old/current DHCP lease and simply re-issue it with the same expiration time.
I'm on DSL/PPPoE, so this may not apply, but: my Asus router has a setting that allows it to automatically reboot. I do this at ~04h00 to get a new IP every day so help with privacy concerns. I generally surf with cookies disabled, so these two things help with the low-hanging fruit of simple tracking techniques. (My DSL modem is bridged.)
Sounds like standard reconnect every 24h, many ISPs do that. reset your modem at a weird time to get the interruption at that weird time in the future.
I think the OP is so eager to get back online he sees 3:40 every day and is using that timepoint as his troubleshooting clue.
However If he were to disconnect 3:10 and then just be offline an hour until plugging the device back he would probably see the reset happen 4:10 going forward.
I had a similar experience to this years ago while working at my mother's kitchen table for while. The network would keep going dead and I had no idea what was causing it.
Eventually, I discovered that it happened every time she used the microwave to heat up a drink or something.
Changing to a different WiFi channel fixed it. :)
If that doesn't fix it, below is how I'd proceed.
Use the trace route networking tool (google it, different syntax on different OS) to some known good public IP address. I usually use 1.1.1.1 or 8.8.8.8.
This tool shows you the path your traffic takes:
$ traceroute 1.1.1.1
traceroute to 1.1.1.1 (1.1.1.1), 30 hops max, 60 byte packets
1 192.168.1.1 (192.168.1.1) 1.286 ms 1.386 ms 1.963 ms
2 192.168.11.1 (192.168.11.1) 2.591 ms 4.342 ms 5.219 ms
...snip...
16 0.ae19.GW8.CHI13.ALTER.NET (140.222.230.223) 42.888 ms 35.742 ms 0.ae20.GW8.CHI13.ALTER.NET (140.222.230.225) 41.060 ms
17 152.179.105.202 (152.179.105.202) 51.913 ms 50.681 ms 55.442 ms
18 one.one.one.one (1.1.1.1) 70.087 ms 65.130 ms 53.607 ms
Run this command at 3:39. Then run it again at 3:40. Then again at 3:41. Compare results and that should give you a good idea which device is malfunctioning at that time.
Some routers also have a ping command baked into them. If you can make it constantly ping 8.8.8.8, while you run the test above, it may help you. In the case where your traceroute stops at your own router, you can look at the ping from the router itself, and see if it also stopped:
A) If the traceroute stops at your router, but the router ping is not interrupted, then something in your router is flaking out.
B) If the router ping is also interrupted, then the problem is "upstream" from you. Maybe the cable modem (or whatever device) that is upstream from your router.
If you decide the problem is upstream, contact your ISP. If it's local, investigate and/or replace the flaky device.
HTH.