YIKES!!! 5GHz Wireless speed has dropped 90%!

[donawalt]

I won't bore you all with the discovery and investigation details, but I am seeing WiFi speed on the 5GHz channel, right next to the the RBS960s AND RBR960, of about 15Mbps-50Mbps on a 2GB/200MB Comcast service! This started all of a sudden last night, with nothing being done to the network prior.

- No settings have changed in at least 2-3 days, probably more;

- This happens to multiple devices, iPads, iPhones, Macs

- 6GHz works fine. I can take my iPhone, put it next to any RBR/RBS, and run a speedtest at 6GHz - I get 1400 Mbps. I turn off WiFi 6 on the device, pushing it to 5GHz, and I get 15-50Mbps;

- Direct Wired Ethernet devices (to the 2.5GHz multi-gig switch) are still working fine with proper speeds.

- After trying many troubleshooting ideas without success, I ultimately powered down the entire network in sequence, including the modem - I powered up just the modem and router, and the same thing happens at 5Ghz!

There's no way 5GHz could have been turned off or greatly minimized any way, is there? the 5GHz AX setting is still enabled.

My configuration:

-NG CM3000 modem -> NG Orbi RBR960 router -> NG XS508M multi-gig switch -> two RBS960 satellites (ie Ethernet backhaul)

- There is also a NG GS348 Gigabit switch connected to the router, which has lower speed devices and unused room outlets on it.

Help! What can I try?

[plemans]

Does it matter if its connected to the router or the satellites? 

I know its a scorched earth attempt but did you try the old "factory reset" option?

[donawalt]

Hi @plemans no, it doesn't matter - it can be connected to the router or either satellite, and the very low 5GHz speed tests are the same. 

I suspect I may have to do the whole factory reset and build from scratch. Bad time in my week for this to happen ☹️  But wow is it PAINFULLY slow...we have gotten used to these faster Gigabit+ wifi speeds haven't we?

[plemans]

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  But wow is it PAINFULLY slow...we have gotten used to these faster Gigabit+ wifi speeds haven't we?

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For sure! I remember a couple months ago getting bumped up from the 40mbps upload to 240mbps on xfinity and its been a remarkable difference in performance. Made me realize how nice the fibre people had it. 

[plemans]

did you try the old "change the 5ghz channel"? 

[FURRYe38]

Was this happening before you changed to the new LAN switches? 

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@donawalt wrote:

I won't bore you all with the discovery and investigation details, but I am seeing WiFi speed on the 5GHz channel, right next to the the RBS960s AND RBR960, of about 15Mbps-50Mbps on a 2GB/200MB Comcast service! This started all of a sudden last night, with nothing being done to the network prior.

- No settings have changed in at least 2-3 days, probably more;

- This happens to multiple devices, iPads, iPhones, Macs

- 6GHz works fine. I can take my iPhone, put it next to any RBR/RBS, and run a speedtest at 6GHz - I get 1400 Mbps. I turn off WiFi 6 on the device, pushing it to 5GHz, and I get 15-50Mbps;

- Direct Wired Ethernet devices (to the 2.5GHz multi-gig switch) are still working fine with proper speeds.

- After trying many troubleshooting ideas without success, I ultimately powered down the entire network in sequence, including the modem - I powered up just the modem and router, and the same thing happens at 5Ghz!

There's no way 5GHz could have been turned off or greatly minimized any way, is there? the 5GHz AX setting is still enabled.

My configuration:

-NG CM3000 modem -> NG Orbi RBR960 router -> NG XS508M multi-gig switch -> two RBS960 satellites (ie Ethernet backhaul)

- There is also a NG GS348 Gigabit switch connected to the router, which has lower speed devices and unused room outlets on it.

Help! What can I try?

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[donawalt]

@plemans - re: did you try the old "change the 5ghz channel"?  - good idea I'll try that!

@FURRYe38 - no, never saw this in my life on a home network before last night!

[donawalt]

@plemans I changed it from 48 to 44 - waited to see it update on my WiFi analyzer app - and tested it, No change in performance. I took this snapshot from the signal analyzer, as you can see (highlighted line) it believes it's a strong signal on 5 GHz with up to 2402 Mbps bandwidth. This is so odd.

[plemans]

and your 2.4ghz channels are 40hz wide so there really shouldn't be much for interference on those channels. 

What link speed are your connecting devices getting? 

Are you using armor? Parental controls?

[plemans]

The 2.4ghz reference was just it'd be 20hz wide if you had a bunch of wireless signals around you. It won't impact the 5ghz. I'm sure you're aware of that, Just an observation

[donawalt]

- FWIW I have had "Enable 20/40 MHz Coexistence" disabled forever.

- Any device that I try Ethernet connected is getting 2250-2350 Mbps

- No Armor, parental controls, VPN, IoT network, Guest Network, dedicated 6GHz network

[donawalt]

Nothing but DHCP messages in the router log. Modem log is clean (although there's no rationale it would be that imho). I tried multiple speed tests too of course, hard reset my iPhone and iPad since they both show it.

I verified this with a late model MacBook Pro where I turned off 6GHz, and also on an 8 year old Dell Precision that only does 5GHz. Both the same.

[FURRYe38]

How many days since you installed the new switch did you see this?

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@donawalt wrote:

@FURRYe38 - no, never saw this in my life on a home network before last night!

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[donawalt]

@FURRYe38 I got the switch April 23, installed it that evening, So it happened 24 hours later. But I did power everything off except the modem and the router (no switches or RBSs) and it still happened.

[FURRYe38]

Wondering if something with the new switch maybe causing this. If you hadn't seen this prior and now you are...

@Straq @SLK-Purdue 

[donawalt]

but it couldn’t be the switch, since I duplicated the very slow Wi-Fi speed with just the cable modem, and the Orbi router running?

[plemans]

if you turn on the 5ghz gues network or Iot network, is it slow too? 

[FURRYe38]

So just cable modem, RBR and switch was disconnected from the RBR? 

Could IPv6 be doing anything? Tried it disabled again? 

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@donawalt wrote:
but it couldn’t be the switch, since I duplicated the very slow Wi-Fi speed with just the cable modem, and the Orbi router running?

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[donawalt]

Hi, PV six is still working fine.

Not sure I understand what you meant by this- So just cable modem, RBR and switch was disconnected from the RBR?

I’ll try the guest Wi-Fi network, good idea.

I tested and verified that the Wi-Fi speeds were slow with just cable modem, and RBR running and connected. Everything else was powered off.

[FURRYe38]

New protocol huh HI, PV six? LOL 

Yes what wanted to confirm was just the cable modem, RBR alone. Something seems to got the RBR in a bad state seems like. 

So confirm, speeds still bad with 5Ghz or has it returned to good operation currently? 

[donawalt]

LOL "HI, PV six" - That'a what Siri think IPv6 is!

Speeds are still bad on 5GHz only - 30-50Mbps, 6GHz gets 1200-1400Mbps at the same position very close to RBSs or RBR - all three.

So I am going in to turn on the Guest network - and I noticed this for my existing network. What is this? Man things are getting weirder and weirder...

[donawalt]

I tested with the Guest network - 5Ghz works! I got 800 Mbps on my iPad. I got 800 Mbps on my iPhone too. But I went back to my regular networks, 50 Mbps.

[plemans]

So we know it isn't a hardware failure. 

Did you try a factory reset? It might be the fastest option

[donawalt]

I am also thinking that may be my best option. I should be able to do that tomorrow.

[FURRYe38]

Your using Google IPv6 DNS right? 
Can you try a different IPv6 DNS service? Cloudfare and Quad9? 

Ya, something is happening on the 5ghz radio. 

I suppose you don't have any 6Ghz devices hanging around do you? 

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@donawalt wrote:

LOL "HI, PV six" - That'a what Siri think IPv6 is!

Speeds are still bad on 5GHz only - 30-50Mbps, 6GHz gets 1200-1400Mbps at the same position very close to RBSs or RBR - all three.

So I am going in to turn on the Guest network - and I noticed this for my existing network. What is this? Man things are getting weirder and weirder...

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