Periodic Internet Connection Loss with GL-AXT1800

Very strange issue - periodic internet loss. Laptop/phone stays connected to router and router stays connected to the ISP-issued router/modem but the router<->internet connection is lost for about 60 seconds after which it comes back and remains active for around 30 seconds. This strange behavior is observed with both wired and wireless connections to the router.

Restarting the router has no effect. Restarting the modem has no effect.

I doubt that this issue is specific to the GL-AXT1800 as the same behavior is also observed with an Asus and a DLink router - internet connection for 30 seconds then lost for about 60 seconds. All the while my laptop ↔ router ↔ modem connection remains active; I can access the router admin page and the ISP modem admin page (and the modem says it’s connected to the internet!).

Before today, I never encountered any issues.

I can establish a stable internet connection to my laptop using a wired connection direct to the ISP modem. No breaks in internet connection are observed.

My office ISP in Chicago is Comcast Business. Comcast phone support reset the modem and told me that it is in ‘perfect’ health and, therefore, the router must be the issue. Since three separate/independent routers with three different manufacturers all show this on->off->on->off behavior with the same period I think it is very unlikely that the individual routers are at fault.

Furthermore, taking the GL-AXT1800 router home, where internet is through a different ISP (astound/RCN) the router works flawlessly.

I wonder if Comcast’s modem is doing something(?) that is crashing(?) the internet connection or if the network topology(the way devices are connected together) is causing some kind of periodic destructive network interference.

As an amateur I don’t know what other diagnostics I can perform to narrow down potential issues.

Below is timestamped laptop ping output:

9/13/2023 9:25:03 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:25:07 PM - Request timed out.
9/13/2023 9:25:10 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:25:13 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:25:17 PM - Request timed out.
9/13/2023 9:25:18 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:25:19 PM - Reply from 172.217.4.36: bytes=32 time=14ms TTL=115
9/13/2023 9:25:20 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:25:21 PM - Reply from 172.217.4.36: bytes=32 time=14ms TTL=115
9/13/2023 9:25:22 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:25:23 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:25:24 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:25:25 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:25:26 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:25:27 PM - Reply from 172.217.4.36: bytes=32 time=19ms TTL=115
9/13/2023 9:25:28 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:25:29 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:25:30 PM - Reply from 172.217.4.36: bytes=32 time=14ms TTL=115
9/13/2023 9:25:31 PM - Reply from 172.217.4.36: bytes=32 time=13ms TTL=115
9/13/2023 9:25:32 PM - Reply from 172.217.4.36: bytes=32 time=16ms TTL=115
9/13/2023 9:25:33 PM - Reply from 172.217.4.36: bytes=32 time=22ms TTL=115
9/13/2023 9:25:34 PM - Reply from 172.217.4.36: bytes=32 time=16ms TTL=115
9/13/2023 9:25:35 PM - Reply from 172.217.4.36: bytes=32 time=16ms TTL=115
9/13/2023 9:25:36 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:25:41 PM - Request timed out.
9/13/2023 9:25:42 PM - Reply from 172.217.4.36: bytes=32 time=16ms TTL=115
9/13/2023 9:25:47 PM - Request timed out.
9/13/2023 9:25:52 PM - Request timed out.
9/13/2023 9:25:57 PM - Request timed out.
9/13/2023 9:25:59 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:02 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:06 PM - Request timed out.
9/13/2023 9:26:09 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:12 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:15 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:18 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:21 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:24 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:27 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:30 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:33 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:36 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:39 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:42 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:26:44 PM - Reply from 172.217.4.36: bytes=32 time=2067ms TTL=115
9/13/2023 9:26:44 PM - Reply from 172.217.4.36: bytes=32 time=20ms TTL=115
9/13/2023 9:26:45 PM - Reply from 172.217.4.36: bytes=32 time=14ms TTL=115
9/13/2023 9:26:46 PM - Reply from 172.217.4.36: bytes=32 time=16ms TTL=115
9/13/2023 9:26:48 PM - Reply from 172.217.4.36: bytes=32 time=16ms TTL=115
9/13/2023 9:26:49 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:26:50 PM - Reply from 172.217.4.36: bytes=32 time=20ms TTL=115
9/13/2023 9:26:51 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:26:52 PM - Reply from 172.217.4.36: bytes=32 time=14ms TTL=115
9/13/2023 9:26:53 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:26:54 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:26:55 PM - Reply from 172.217.4.36: bytes=32 time=16ms TTL=115
9/13/2023 9:26:56 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:26:57 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:26:58 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:26:59 PM - Reply from 172.217.4.36: bytes=32 time=16ms TTL=115
9/13/2023 9:27:00 PM - Reply from 172.217.4.36: bytes=32 time=17ms TTL=115
9/13/2023 9:27:01 PM - Reply from 172.217.4.36: bytes=32 time=16ms TTL=115
9/13/2023 9:27:02 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:27:03 PM - Reply from 172.217.4.36: bytes=32 time=16ms TTL=115
9/13/2023 9:27:04 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:27:05 PM - Reply from 172.217.4.36: bytes=32 time=16ms TTL=115
9/13/2023 9:27:06 PM - Reply from 172.217.4.36: bytes=32 time=15ms TTL=115
9/13/2023 9:27:07 PM - Reply from 172.217.4.36: bytes=32 time=16ms TTL=115
9/13/2023 9:27:08 PM - Reply from 172.217.4.36: bytes=32 time=17ms TTL=115
9/13/2023 9:27:12 PM - Request timed out.
9/13/2023 9:27:17 PM - Request timed out.
9/13/2023 9:27:22 PM - Request timed out.
9/13/2023 9:27:27 PM - Request timed out.
9/13/2023 9:27:32 PM - Request timed out.
9/13/2023 9:27:37 PM - Request timed out.
9/13/2023 9:27:42 PM - Request timed out.
9/13/2023 9:27:47 PM - Request timed out.
9/13/2023 9:27:51 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:27:54 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:27:57 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:28:00 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:28:04 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:28:07 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:28:10 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:28:13 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:28:16 PM - Reply from xxx.xxx.xxx.xxx: Destination host unreachable.
9/13/2023 9:28:16 PM - Reply from 172.217.4.36: bytes=32 time=19ms TTL=115
9/13/2023 9:28:17 PM - Reply from 172.217.4.36: bytes=32 time=18ms TTL=115
...

If you didn’t change anything then it’s not an issue you can solve.

Over wireless it’s showing signs of a dfs channel check that fails but if it happens over ethernet too then it must be the router you’re linking to having an issue.

There are two things you can try:

  1. Change the cable from Comcast to the router.

  2. Maybe your Comcast router is trying not to accept new routers. So find one that works and clone the mac address to the new router. Or you can try to clone your computer’s mac address to the router.

  3. When this happens, get the log from the router (i.e. the GL-AXT1800). You can get the log from the web panel->system->log. The log you posted is from your pc which don’t say the reason of the router.