[SOLVED] Troubleshooting intermittent connection issues ?

[anvoice]

There's someone in the home working from a certain room where wifi may have trouble reaching. Not a basement, nor particularly far from router, but I get constant complaints that he can't connect to his mail server (university mail system) and "other sites". His patience is limited leading to issues with troubleshooting. I tried running speetests on his computer multiple times, but they all come back with less-than-ethernet, but consistently respectable speeds of at least 140Mbps (way more than what's needed for mail).

I was the one who set all networking up, so I'll have to fix whatever is broken. Router is too far from that room and upstairs, so can't do permanent ethernet unless I go ethernet over powerline or MOCA route.

Which leads me to the question: is there a good method to troubleshoot likely intermittent wifi issues to particular sites? I am particularly interested in trying to test connection to the specific mail server he is trying to access but have no idea how to find its IP address, or what to do if server doesn't respond to ping.

Details:
Computer in question is a Dell XPS 15 2020 laptop, running both Windows 10 and Ubuntu 24.04 on separate SSDs. Not sure which OS is giving him the issue, will need to ask. Further, the computer never gave me wifi issues when I used it before a few years ago. I tried "ping -t 8.8.8.8" on most computers at home for an hour or so and so with no data loss, leading me to believe connection is consistently present on that computer. Router is a TP-link Archer AX50, a wifi 6 machine.

Someone else at home used their 5G phone a couple of times now as a hotspot for that computer, at which point he claims he was able to access his sites with no issue, so I thought maybe ISP is the problem. On the other hand, I'm personally on the same wifi constantly with all my devices (just not in that room) and have no issues accessing anything most of the time, which casts doubt on that theory. I temporarily threw an ethernet cable downstairs so I can now quickly test at least if wifi is the culprit when the issue next comes up, assuming I'm ther at the time and he cooperates. In the meantime, I'd really appreciate any advice for troubleshooting.

 

[bill001g]

You have done most the steps I would recommend. Since you see no loss to 8.8.8.8 it in general means the network is fine. If other addresses do not work then it would be server or something else in the path outside your house that you have no control over.

Just as a random thing to try, try to disable IPv6. For unknown reasons many people have issues when they use IPv6. IPv6 many times takes a different path in the internet and if his machine was using IPv6 or more likely a mix of IPv6 and IPv4 you can get very inconsistent results.

The other difference between a hotspot and your normal connection is the DNS being used. I would set the dns to 8.8.8.8 or 1.1.1.1 in the nic settings. I would in the long run actually also turn on the encrypted dns option when things are stable.

Running a ethernet cable is going to be your best option to eliminate the wifi as the cause. You already know about powerline and moca if it does prove to be the is

 

[anvoice]

You have done most the steps I would recommend. Since you see no loss to 8.8.8.8 it in general means the network is fine. If other addresses do not work then it would be server or something else in the path outside your house that you have no control over.

Just as a random thing to try, try to disable IPv6. For unknown reasons many people have issues when they use IPv6. IPv6 many times takes a different path in the internet and if his machine was using IPv6 or more likely a mix of IPv6 and IPv4 you can get very inconsistent results.

The other difference between a hotspot and your normal connection is the DNS being used. I would set the dns to 8.8.8.8 or 1.1.1.1 in the nic settings. I would in the long run actually also turn on the encrypted dns option when things are stable.

Running a ethernet cable is going to be your best option to eliminate the wifi as the cause. You already know about powerline and moca if it does prove to be the is

Thanks for the suggestions. I did throw an ethernet cable downstairs and when the issue resurfaced, plugged it in. Computer was back online immediately, which means that something about the wifi is at fault. My guess is it might be a combination problem: if signal is weak/lost periodically, the hardware/software on the computer might lose connection and then fail to reconnect. This is also supported by the fact that the user claims he often does a disconnect followed by a reconnect to wifi, and computer continues working for a while.

I did not know about the IPv6 issue. I'm going to guess that it's unlikely to be the problem here since connection immediately returns after physically connecting with ethernet cable.

For now, I'm assuming wifi is not a viable long term option in that room, so I ordered a pair of moca adapters.