Question Slow router wifi on an extensive home network, but cannot find a solution.

[ZhaoYun]

Greetings! I have a rather extensive network setup, and recently, one of the routers has stopped providing acceptable wifi speeds on either channel. It worked just fine until a few weeks ago, and no changes have been made to my knowledge.

My setup: I have an ATT fiber router/modem, connected to an ASUS router with wifi 6, I have a 100ft CAT 8 ethernet cable (all cables are CAT 6-8) connected to the WAN port of the 2nd Asus router. I have tested the cable plugged in, speeds are fine, as are speeds when plugged into the router's 4 ports. However, wifi speeds are very slow on the 2nd Asus router for some reason. I have used a wifi analyzer and moved 2.4 to channel 9, as no other device nearby was on that channel. I have many neighbors with AT&T routers as well. The wireless connection to the AT&T router isn't good for any device that doesn't have a wifi 6+ adapter, even though it's backwards compatible. The 1st Asus router only broadcasts wifi 6e, so most devices cannot connect to it. I swapped the 2nd Asus router out with another Asus router to test that I know works, and the same issue occurs. I set the 2nd router in AC mode, but no change in speed either. I'm honestly running out of ideas, DHCP is disabled on the 2nd router as well. Can anyone think of something I may have overlooked? Prior to this happening, the 2nd router was just setup like a regular router and worked just fine. Any help would greatly be appreciated! Thank you for taking the time to read this as well!

 

[Ralston18]

Cat 8 cable? How extensive is your network setup..... ?

Start here:

https://forums.tomshardware.com/threads/ethernet-switch-2-5gb-and-higher.3871627/

Especially starting with Post #7 ( @bill001g) and the following posts.

 

[ZhaoYun]

3 routers (AT&T, and 2x Asus), 3 switches (2x 8 port and 1x 4 port). I have bypassed the switches for testing purposes. So only the routers are part of the equation at this time.

 

[bill001g]

So if we assumed you paid more than $100 for your cat8 cable maybe it is real. Real ones are extremely expensive and are generally only sold by vendors who only sell equipment to data centers. You can get them but they are not cheap. The other thing that makes it very likely that you cat8 cable is fake is the maximum length is 30 meters which is just under 100 feet. No valid vendor would sell a 100ft cable.

In any case the cable will likely run 1gbit just fine.

So if I understand correctly you have your asus router plugged into the att router with ethernet and then you plug a second ethernet cable into the att router and you get good speeds. This would mean it is only a wifi issue.

What speeds are you considering "slow". You talk about using 2.4g. You are going to be lucky to get 100mbps on 2.4g. There just is not enough bandwidth. In addition your nieghbors are not just using 1 of those channels.
Most people are using channels 1-6 or 5-11. You can only fit two signal with no overlap when people use 40mhz channels which is very common no days. You have similar problems on 5g where they are attempting to use 160mhz channels. You must assume every channel is in use and it does little good to even try to tune it. The wifi scanners are worthless. They only show the routers they do not show end devices so you have no idea which routers sending alot of traffic or if they are just sitting idle sending out their id number.

I don't understand why you think the first router only broadcasts wifi6e.....unless you did something crazy like disable the 2.4g and 5g radios. All routers are backward compatible. They will connect with very old wifi1 devices by default. There are technical reasons you do not want to support really old stuff but out of the box the routers will connect to these devices.

The only reason the devices can't use wifi6e is they don't have a chip that can run 6ghz. They can connect to the 2.4 and 5 chips in the router.