Home Ethernet failure

boardtc

Hi,

We are Cat6 smart wired in our house and with lots of concrete and not having WiFi everywhere we rely on Ethernet for internet access - 2 of us are WFH.

Yesterday it stopped working out of the blue on all Ethernet ports. After plenty of testing: the Eir router has an internet light, WiFi works. We have a TP-link TP-SG1024D (https://manualsbrain.com/en/manuals/1236545/), it's a dumb switch, plug and play and has worked no bother for a few years. The power light is on, all the lights show/flash including port 23 from the Eir router.

I'm not 100% sure but I believe this unmanaged switch should be pingable on 192.168.0.1 but it does not respond. That might be a red herring?

Out of desperation I rang Eir and they actually detected a fault when they ran their tests! An engineer may call tomorrow. But there can't be an issue with the line since WiFi works!

We are really snookered here. Any thoughts please on what might be wrong?

TheChizler

Maybe try using Fing on desktop and mobile to do a scan of your network and see what devices are contactable, you can rule out the switch or individual ports on it and the Eir gateway.

Those TP-Link switches are pretty solid. If its unmanaged it won't be contactable at all.

I presume you've rebooted everything?

windowcills

Are all the network activity lights on the switch flashing at the same time, if they are then unplug the cables (with activity) for a minute, just one at a time, until it stops

Enjoy :)

boardtc

Sound. Fing is a nice app. It found the printer, the eir router and my phone. Where does that leave us? I power cycled the switch too previously. I had to work away today as a result, laptop still not connecting when I got back.

boardtc

9 lights on, 6 flashing continuously. What does that mean? I did that and only flashing one now is 23 from the router. What does that tell?

ECO_Mental

https://www.boards.ie/discussion/2058321787/home-ethernet-failure

Did you plug an ethernet cable directy into the Eir router and did get an internet connection on your laptop...if thats working then its your switch thats given up for some reason. I knwo nothing about those TP link switches but obviously power cycle everyting including the eir router.

If that still doesnt work and you are getting internet at the Eir router then short term get some long ethernet cables or pick up another swicth in Currys

Hijpo

When you say all eth ports im not sure if thats all eth on router or switch or both so...

If it was me i would plug a laptop direct to the ethernet port on the router and check Internet connectivity to rule out an issue at the router.

Then I would test for connectivity from the router to the switch by ruling out the current cable and run a temporary cable between them if possible.

How many eth points are in the home? Do they all feed back direct to that switch?

TheChizler

https://www.boards.ie/discussion/comment/121344554#Comment_121344554

The switch is fine so, it's likely something in the Eir router. What specifically isn't working? Web access?

Try pinging the router on the address you got from Fing, then something on the web, google.com and a raw IP address such as 8.8.8.8, if the IP address works but not the former then it's probably a DNS issue.

boardtc

Baffling.... The printer is connected by Ethernet also. Fing finds it but not my 2 laptops that are also connected via ethernet in same room.

About 30 internet points all coming back to the patch panel, I have only a couple of handfuls patched to the switch.

Update.... I disconnected a bunch from switch and only left one of my laptops active I think and it had internet again! Then I reconnected others and the laptop went off line again. Looks like a switch failure? I purchased it in 2019 it failed in 2020 (no lights) and they did a warranty replacement.

I guess I can patch straight to the router now until I have a replacement with problem identified. Thanks!

TheChizler

Could be but I'd be a bit surprised for it to fail in such a weird way out of the blue, but weirder things happen. What's your test for saying things are working or gone offline? Are you scanning from one of the laptops connected to the switch or from your phone over wifi through the router?

smuggler.ie

https://www.boards.ie/discussion/comment/121344809#Comment_121344809

Disconnect ALL from switch. Reconnect one-by-one or test every port on the switch with laptop direct connection.

If its not switch failure, perhaps you have created "network loop" - two cables from switch connected to router or one cable/link both ends in the switch. That would take network "down" in few seconds.

ItHurtsWhenIP

@smuggler.ie may be onto something here with the "network loop", but this statement:

@boardtc Update.... I disconnected a bunch from switch and only left one of my laptops active I think and it had internet again! Then I reconnected others and the laptop went off line again.

makes me wonder if there's a second DHCP server going somewhere and giving out conflicting IPs.

smuggler.ie

Secondary DHCP is possibility alright.

Providing laptop was left connected while the rest of cables plugged back into switch, so the laptop should retain IP config from "first" DHCP (that would be Eir Router as laptop had internet).

Not sure if re-introducing "second" DHCP would effect this particular laptop, that is already with IP config (until lease renewal), at this point. If secondary on same IP as first, i guess it would/could. Will do the test just out of curiosity, later.

OP have checking to do....

any "new" devices introduced, additional wires patched or some devices reset?

How many leads you have on Eir router? - if more than one that goes to the switch, can you trace and see where they end-up.

Trace every cable on the switch end-to-end to confirm non of them return back to switch or into router.

Do you have another switch elsewhere? i mean as part of the network.

Also, when checking Eth for internet, make sure turn off WiFi on laptop.

boardtc

https://www.boards.ie/discussion/comment/121349029#Comment_121349029

No, I have nothing like that, no other switch either. I am using all 4 into the router now that the switch is bypassed and sent back to TP-link for a warranty replacement. Normally I have 1 doing got the eir router to the switch. There was nothing new added when it failed.

slystallone

https://www.boards.ie/discussion/2058321787/home-ethernet-failure

What do you mean by smart wired? Is it different from wired?

boardtc

I just meant to distinguish cat6 wiring from regular electrical wiring.