@Linfeng 

I almost suspect it DOES not log that? Yes, the router will know, as will your devices. The Modem will log that though. Most modems will allow you to see the Log by using 192.168.100.1 as the URL (unless you have a recent Charter supplied modem, they lock the GUI so you can't see anything, but that isn't who you have it seems).

May I as what good is knowing this? Knowing will not stop it.

Complain I guess to the ISP, they should be able to see it in the logs and maybe even a reason why?

What has me puzzled it it happens in your home AND at work? Same router, or same router model? Is 'work' in your home or somewhere else?

I got the following reply from the TP-Link support. Yet, I am not sure if the agent was simply trying to push the case off the table.

When there is "no internet connection", the local management page for the router shall complain about it. It is hard to believe logging these events should be new feature demanding the R&D team to step in.

@ArcherC8 I have two routers, AX6000 V1 at home, and Archer A6 in the office. They are relatively new and I bought them in 2019. I have a very simple topology, where all things are connected either directly to the router or through another tp-link switch.

@IrvSp At home, I was able to access the Xfinity modem at 10.0.0.1. It did log events with "[Harvester] ..." tags, but no one was able to tell what was actually going on. I posted about this on Xfinity forum, under title "xFi no internet access: Harvester code and inconsistent access to 10.0.0.1 under bridge mode" (the forum does not allow me to add external links).

At work (on a University campus), I don't see a compiling reason to bug the admin yet. I started using my office when it gets hot in the afternoons, and may only spend a few hours a day. Over the past week, I only had one "no internet" event. It came back on after a few minutes.

Justification on "what good is knowing this": Overall, it takes a lot of effort to figure out what was happening at the other end of the "WAN port", be it fetching logs from the ISP's modem or trying to get logs from admin about Ethernet ports on the wall at work. Leaving troubleshooting aside, since the router is "my own", I should be able to read off what it knows about w.r.t. its own internet connection. This can serve as a very good first step for troubleshooting, in particular when "no internet events" should occur randomly.

RE: troubleshooting. After trying to work with Xfinity, my ISP at home, for a good number of months, I start to treat troubleshooting as a separate issue. The random "no internet" events started in October last year, and it was until last Sunday that someone finally figured out what was happening on their side. The root cause was some low frequency from their signal box outside my apartment.

Now I would tentatively conclude that tp-link does not log "no internet events" on its router.

I was thinking about unplugging the WAN cable as well. I haven't got a window to pull for it :)

Will update here should I catch it in the log, then. I would treat the "No Internet" events at home and at work as two standalone cases.

The Xfinity difficulty was mainly due to their poor support person(s) at the other side of the phone line. They were not able to dispatch the needed personale to show up and fix the signal box on-site. At work, I should definitely talk to my admin should the outage persist. It should take a few more warmer afternoons to send me to my office.

@IrvSp , thanks a lot for following up.

@Linfeng Keep Posting this content i love to read this

A new post from @michaelDom triggered an email alert. Have fun reading alone. I have a rather disappointing note to make, though.

"Logging the no internet from whichever WAN source port is a "new feature" that demands R&D effort at tp-link." --- A response from a senior technical support person.

I don't quite get the rationale behind pointing fingers to the R&D team for this stupidly simple feature. As it is clear per the existing interface, the router itself should complain about a "no internet event". It takes marginally very low effort to keep a log of these.

Personally, I end up pinging a bunch of local and remote IP and write the full ping-log to a local file. This DIY approach takes, well, marginally low effort to parse out.

@Linfeng 

I am pretty sure the Router knows when it has no Internet. The main GUI will tell you that with a ! on the Main GUI page in the Globe. Usually has a Check Mark on it but if no WAN, the ! sign.

Other than being able to tell your ISP the modem appeared to drop the signal to the router at such and such a time, I'd think the value of the information is minimal, but yes, nice to have.

The logs of the Modem should have that same info, at least if it is the external WAN connection to the Modem. If it doesn't, and you might be able to see the log on the modem yourself, then it is possible the modem is going bad or overheating.

Why has the ISP not replaced your modem to isolate the issue?

Linfeng wrote

A new post from @michaelDom triggered an email alert. Have fun reading alone. I have a rather disappointing note to make, though.

 

"Logging the no internet from whichever WAN source port is a "new feature" that demands R&D effort at tp-link." --- A response from a senior technical support person.

 

I don't quite get the rationale behind pointing fingers to the R&D team for this stupidly simple feature.

Simple, who do you think changes the design of the code? Implements the code change? Not the 'support team', they handle 'old' code.

Was it sent to R&D to look at? That is the question you should ask back of the Support person.

@IrvSp I agree with everything you said. Yet, it was not a productive conversation when the support person does not answer my initial simple question: where in the system log can I find an indication for "no internet event". Pushing for R&D is more of a joke as I see it. And, like other occurrences of pushing the matter to another team in a corporate setting, I believe this is going nowhere.

RE: ISP - I tried to deal with my ISP. I got their modem replaced multiple times. Still, their modem should restart on itself. This leaves a 5-15 minutes window where I have no internet at home. A technician went on-site several weeks ago and fixed their cable box. Yet, last Friday, the ISP's modem restarted itself 5 minutes before a scheduled meeting. It was a lot of fun hassling to my office to host that meeting in time. 

@Linfeng 

The problem happening with a different Modem begs the question of if your electrical connection might be the problem?

Are you on a 'Surge Protector'? Most ISP's do not suggest doing this. However, a drop below a certian voltage, surge above a value, or even noise could cause a reboot.

I have mine on a UPS which isolates the modem and router from voltage problems (including a power drop). These draw very little current, and during a recent Hurricane I had over 5 hours of Internet (as long as my ISP's nodes power held up which are also on USP's) usage on my devices (iPad and Phone via battery power that lasts for days, or my PC also on a UPS but with only around 25 minute uptime capability for tower and display).

Might be worth looking at a UPS, and type will do for a modem and router. If you are having voltage excursions that will filter them out, and ALSO log and instances and values.

I've got CyberPower and APC units here. PFC type for PC's and AVR for the modem/router.

In order to see the modem/router logs you do need to connect the USB output of the UPS to a PC and Load S/W to get the data. Pain for me to do with the modem/router UPS as it isn't close to a PC.

These units could run around $100 with enough battery power. Maybe you could borrow one from a friend rather than purchase one to see if it helps?

There is always a chance electric power isn't the problem? If not, I'd look at the Power Supplies for both the modem and router? Either could be a problem? Even try using a different wall socket for them?