Ping spikes after connecting new switch and certain desktop PC

[saschan2]

Hi!

I have the following network configuration:

Previously I had an old TPLink Wifi router where I put in the new TPLink Switch. This was necessary because of getting a second PC2 that I wanted to communicate with the existing PC1 at high speeds via LAN.

Which worked pretty nice for a day...

The next morning I noticed that the connection on PC1 was VERY SLOW. Pinging the Router brought up pings of 3000+ms.

This happens for all devices. But it ONLY happens when PC1 is connected, which was never causing any problems before. As soon as PC3 starts loading something from the internet, the pings to router on PC1, PC2 Notebook start to detoriate. As soon as PC1 gets disconnected, pings improve immediately.

I replaced the network cable between TPLink Switch and PC1 to see if that could be a cause. But it didn't change anything.

I'm at a loss. I thought it may be a certain number of devices that the AC1750 router can handle behind those two switches. But currently it's only the two PCs, Notebook and NAS that are connected.

Thanks for any help!

 

[camieabz]

Swap the TPL switch network ports around (or swap NiC ports on specific PCs, if possible).

If that doesn't change things, check logs to see what's going on on the network (or use Wireshark on each PC to monitor activity).

If that doesn't shed any light, start looking at the PCs' networking behaviour in the sense of Windows updates (especially Windows 10 telemetry), background processes, or even malware.

Failing that, it might be network card drivers, or card conflict issues on the network.

 

[failboat]

Is it possible to run more wires out to each device? Ideally you want the modem->router->switch in the same place then one wire out to each device or access point. nothing on wired should slow down if it's not being swamped, even with your setup. check resource monitors to see if there is a lot of traffic. are you running any extra services on the switches?

currently transfer from pc to nas will swamp your lines 3,4 coming out of router. If you can't move to one switch move the nas to the switch where the clients use it the most.

one other thing is to check the static ips of anything new added in. make sure it's not conflicting with anything. nmap can scan for you. check the dhcp lease table and log in to each static web interface.