@scottuf 

There is no way to do what you want.

TP-Link has decided that a WAN failure is not important enough to include in the logs or notify you in any way.

Yes, you read that right. Yes, TP-Link is well aware of it. Yes, many others have complained about it to them. Yes, it is quite stupid. No, there is no fix.

See here for more:

https://community.tp-link.com/en/business/forum/topic/504082

@CutterKin

That is quite disappointing considering that it seems to be a major feature of the router.

What I did end up doing though was setting my WAN/LAN1 to Always up. For whatever reason my Eero could never speed test on that ISP.  I think they have something wonky with their setup that prevents the routers from pinging and the like. I tested failover by unplugging my WAN fiber from my ONT and pinging from my laptop and it didn't drop a single ping, so at least I know the failover is working, which is really all I care about.

Just wish there was a way to know it happened.

BTW - Read your thread. Did you go with another device that works similarly, but actually logs? I don't want to spend a ton, but having the functionality would be nice.

  @scottuf 

I spent a whole lot of time experimenting with various dual wan routers. Synology RT2600ac, Cisco RV325, a now obsolete Cisco RV042G, a much newer (and more expensive) Cisco that I can't remember the model name, and an Asus that I also can't remember the model name.

To answer your question, all of the above would properly log every WAN failure (if it detected it in the first place - another whole story...) and most would send to syslog server, email the admin, etc. Only the TP-Link is lacking this obvious feature.

My workplace ending up going with the expensive Cisco units and we continue to use them today. If I seem particularly miffed about this issue, it is because I was the one that pushed to try the TP-Link at work in the first place, and I ended up looking stupid when the unit didn't support this very basic feature. All of them (about a dozen) went back to the vendor. I'm aware of several other lost sales over this dumb oversight too, but I will stop ranting now...

Personally, I kept my TP-Link and still use it. That is why I still hang around here time to time. Every other unit I tested had various other flaws, mostly due to my weird configuration at home, and in the end the TP-Link was the best fit for my personal use. Aside from the lack of proper logging, it is perfect for me in every other regard, which is why I find it crazy they don't fix this issue. It would take what, 12 lines of code?

Anyway, in case anyone is interested, here is my creative kludge to circumvent the issue:

I have both fiber and cable at my house. I setup several rules via group & policy routing that force the Roku on my main living room TV to ONLY use cable and not fail over if it goes out, and my bedroom TV Roku to only use fiber. That way, if one or the other goes down, I will be "notified" rather quickly by someone in my house that one or the other is out since those TV's are on pretty much always when we are home. Works for me. I can expand on how I did it if anyone else ever wants to try something similar.

Or here is a better idea... Hey, TP-Link, FIX THIS once and for all please!

  @CutterKin 

I get it.

Let me ask a related question, since I'm new to this, and given the conversation it's relevant to the issue of failover, though not with logging. When I first set it up and tested it out by pulling the fiber from the ONT but leaving the ethernet plugged in to simulate a down line, my computers had issues with DNS. I could ping an IP (8.8.8.8) but if I put in google.com it would time out. The computer is showing 192.168.0.1 as the DNS, so it's getting it from the TP-Link. The WAN had default Frontier DNS, and the backup had their default of 8.8.8.8/4.2.2.2.  I got around this issue by manually inputting the 8.8.8.8/4.2.2.2 into the Frontier WAN setting, but shouldn't the router automatically switch it's DNS when it failsover?  Perhaps I'm missing something.