Question Wifi slows down considerably with ethernet cable plugged in to access NAS server? EDIT: *(This makes no sense)*

[Ironarmygeneral]

Hi, sorry if the title is a bit misleading--anyway, I am just confused as to why my wifi connection on my computer slows down considerably when I have an ethernet cable plugged in which is attached to my NAS server network which is separate from my main network.

Let me explain.

Due to living with other people, I can't have my NAS connected to my main network (router/modem/etc). My room and my computer are in the basement, and my PC uses wifi which is usually always fast enough for what I need on 5GHz band as it's basically in the room above mine so only a ceiling to go through. Anyway, because I can't have the NAS attached to the main router, I set it up in my closet (huge walk in closet with plenty of space and cooling plus the basement is always cold anyway) and have it connected to the LAN ports of a separate, offline router, and my PC is also connected to the LAN ports on the same router with an ethernet cable running to the PC from the closet. It works, suits me fine. However, I've noticed that when it's plugged in, my wifi connection gets EXTREMELY slow. Sites like Facebook, Gmail, Google, etc that usually take 1-2 seconds to load are now taking a good 15-20 seconds. This is on high speed internet, 5GHz band, expensive router, 300Mbps capable wireless card (in my PC which is a workstation). I tested it over and over, plugging in the ethernet cable to the server and unplugging it and testing speeds. Every time, it's MUCH faster while NOT plugged in. Is my PC trying to ping these sites off both networks or something and since one isn't connected to the internet it switches over to the main router??? Or something along those lines?

Here are some speedtest.net results. (BTW... ethernet plugged in = 7 seconds to load, unplugged = less than a second to load...)

ERM..... before I upload these pics... I just went and did the speedtest... and I am absolutely BOGGLED by this... connecting to the same server, it actually shows I have the EXACT SAME SPEED, but considerably SLOWEER download when NOT plugged into the ethernet cable?? But yet, real world testing shows it's MUCH FASTER? This makes no sense?!?! I thought for sure it'd be MUCH FASTER... but speedtest shows somehow that my speed is faster when I have the NAS network (let's just call it that) plugged in... the heck?? It's not ACTUALLY faster?? Does someone know what's going on???

Anyway, here are the screenshots...

CONNECTED to the NAS network:

NOT CONNECTED to the NAS network:

 

[jsmithepa]

Try disabling WIFI while using ethernet.

 

[neojack]

you have to tell your computer wich adapters to use to reach the needed ressources.

i think your PC try to prioritize the wired network, tries it, then is unable to reach internet, then it tries with the wifi.
if it does it with each packet, the end result is a slow down


they are several solutions :
1 - set your wired network on a different subnet. do NOT indicate a gateway in the ipv4 settings on your adapter.
for exemple. let say your wifi network router adress is 192.168.1.1

on your NAS use those settings :
adress : 192.168.20.20
mask : 255.255.255.0
gateway : set it to manual, but put nothing in there
DNS : Same as gateway

on your computeropen ncpa.cpl
right clic on the wired adapter, properties
in the list,
uncheck IPV6 to disable it
select ipv4 settings. set this
adress : 192.168.20.10
mask : 255.255.255.0
gateway : set it to manuel, but put nothing in there
DNS : Same as gatewa



With those settings, you tell your computer that the wired network is basically a dead-end with no acces to the internet or any network besides 192.168.20.x
your computer would only use the wired adapter for accessing your NAS


2 - other solution : set the priority of the network adapters. i don't really recommend it but hey
windows 10 : https://www.windowscentral.com/how-change-priority-order-network-adapters-windows-10
windows 7 : https://support.microsoft.com/en-us/help/2526067

 

[Ironarmygeneral]

Try disabling WIFI while using ethernet.

Uh, what would that solve? I want wifi to be fast, not non-existent...

 

[Ironarmygeneral]

you have to tell your computer wich adapters to use to reach the needed ressources.

i think your PC try to prioritize the wired network, tries it, then is unable to reach internet, then it tries with the wifi.
if it does it with each packet, the end result is a slow down


they are several solutions :
1 - set your wired network on a different subnet. do NOT indicate a gateway in the ipv4 settings on your adapter.
for exemple. let say your wifi network router adress is 192.168.1.1

on your NAS use those settings :
adress : 192.168.20.20
mask : 255.255.255.0
gateway : set it to manual, but put nothing in there
DNS : Same as gateway

on your computeropen ncpa.cpl
right clic on the wired adapter, properties
in the list,
uncheck IPV6 to disable it
select ipv4 settings. set this
adress : 192.168.20.10
mask : 255.255.255.0
gateway : set it to manuel, but put nothing in there
DNS : Same as gatewa



With those settings, you tell your computer that the wired network is basically a dead-end with no acces to the internet or any network besides 192.168.20.x
your computer would only use the wired adapter for accessing your NAS


2 - other solution : set the priority of the network adapters. i don't really recommend it but hey
windows 10 : https://www.windowscentral.com/how-change-priority-order-network-adapters-windows-10
windows 7 : https://support.microsoft.com/en-us/help/2526067

Changing adapter priorities worked and everything works fine now. Thanks!