Onboard LAN adapter is bad or something else?

[supo]

Hi, internet was working fine until a few months ago when I started to have problems. I'm trying to troubleshoot it and find the root of the issue.. So basically what happens is that after 1-2 days my internet connection becomes very unstable, getting messages like "Resolving host..." on google chrome, websites opening very slowly or not at all, internet connection becomes very bad on every device etc.

My setup is like this:

I have a ISP router/modem that every device at home is connected to, I have also an unmanaged switch connected to the modem because of more ports obviously which is working without issues for years.. My connected wired devices are: 1 PC (connected directly to the modem), 4 consoles, 2 android tv boxes, then rest of the stuff are WIFI connected like cell phones etc.

Everytime my internet connection goes bad, I tried to unplug the ethernet plug of every device one by one to see if there is a problem with a device that's making the network go bad. So what I found out in the end is that internet connection (on every device) works good again if I unplug the ethernet cable from the back of the modem that goes to my PC and plug it back in OR if I just restart my modem.

So I have tried several things, like changing my modem with another one (3 times) giving my PC a static DHCP address, making the lease times longer, trying public DNS servers, changing ethernet cable with a brand new one, updating my network adapter driver etc. but no matter what I try it keeps happening.

Also when the problem happens and I try to ping a website from the command prompt on my PC I get packet losses or the ping does't work at all. But everything (and every devices internet connection) works magically again if I just unplug the PC's ethernet cable and plug it back again, it saves me time from restarting the modem also.

So what can be the problem? Obviously the PC is the culprit as far as I can but everything was working fine for years. Should also mention that this started happening actually when the ISP decided to "upgrade" the lines in the neighborhood, giving out newer modems to everyone and changing the wall sockets in the apartments.. When contacted about the issue however, the ISP says everything looks good on their end, signal is fine bla bla.

I really need help, sorry for long post.

 

[coxhaus]

Your description is not good. I hope you mean the switch and PC are plugged into the router port not modem. I would try plugging the PC into the switch for starters. Assign QUAD9, 9.9.9.9 as your DNS. Then use a spam product like Malware AdwCleaner on your PC. Update your PC to the latest Windows10 updates.

 

[supo]

Your description is not good. I hope you mean the switch and PC are plugged into the router port not modem. I would try plugging the PC into the switch for starters. Assign QUAD9, 9.9.9.9 as your DNS. Then use a spam product like Malware AdwCleaner on your PC. Update your PC to the latest Windows10 updates.

I'm not using a separate router. I'm just using the modem from my ISP which is also a wireless router. I have taken out my own router to for troubleshooting. My PC is wired directly to my modem/router, my switch is also wired to my modem/router.

I have already scanned my Windows with several anti malware and anti virus programs so I don't have anything.

 

[coxhaus]

Good that you have scanned your PC now try the rest of what I posted and we will see if there is a change.

 

[degrub]

Turn off wireless in your PC if you have it.
what happens when only the switch is plugged into the router and all other devices, including the PC are plugged into the switch ?
If you don't have enough ports on the switch, just leave those devices unplugged.

 

[coxhaus]

This is why I asked him to plug his PC into the switch instead of the router. The switch may have protection and the router not. If you are having a switch wireless problem then you need a better switch that has spanning tree that works. I can flip flop back and forth on my Cisco small business switches on my PC between wireless and wire without a single problem. IF they are both on the first is the working one.

 

[supo]

Turn off wireless in your PC if you have it.
what happens when only the switch is plugged into the router and all other devices, including the PC are plugged into the switch ?
If you don't have enough ports on the switch, just leave those devices unplugged.

I don't have WiFi on key PC only LAN port. Hmmm I didn't try that I could try it, but like I said I have to wait for 1-2 days for the problem to occur, it doesn't happen right away randomly.