XR500 Constant 100% CPU

[westy666]

Hi all,

I'm a bit stuck on this one.

Running latest firmware XR500 V2.3.2.134.

Router is running 100% constantly on both CPU's. A reboot doesn't change anything.

Only way I can fix it, temporarily, is to re-flash the current firmware. It'll be fine for maybe 3-4 days then go back to 100% again until I reflash.

Changed my router admin password a couple of times just incase it got hacked and someone uploaded a crypto firmware.

Doesn't seem to affect network speeds. Speedtests run fine.

Only other odd behavior is when this starts my connection benchmark results are gone and the scheduled benchmark isn't there anymore.

Any ideas ?

Thanks

Steve

[FURRYe38 · Accepted solution]

Pressing for 10-15 seconds should be all that is needed on the reset button. 

Ya, I prefer using the ERASE button with in the UI. 

Glad you got it working. Please mark your thread as solved so others will know. Be sure to save off a back up configuration to file for safe keeping. Saves time if a reset is needed.
https://kb.netgear.com/000062080/How-do-I-back-up-the-configuration-settings-on-my-Orbi-WiFi-System

[FURRYe38]

What is all connected to the router when this happens? 

Try disconnecting everything and checking CPU usage to see if it drops in value? 
What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too?
Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended. 

Has a factory reset and setup from scratch been performed since last FW update?

[westy666]

Thanks for the reply.

When it goes to 100% I've tried disconnecting everything except my PC (Including my Virgin Media Superhub 3), even disabled wireless. Still stays at 100%.

Just rebooted it and it's returned to normal. Which is weird as last couple of times it went right to 100% within a few mins.

Gona try a full factory reset but will not know for a few days if it comes back or not.

Checked logs and nothing obvious in there.

[FURRYe38]

Your ISP Modem already has a built in router and wifi. This would be a double NAT (two router) condition which isn't recommended. Disabling WiFi here is not enough. This would be a double NAT condition which isn't recommended. https://kb.netgear.com/30186/What-is-Double-NAT
https://kb.netgear.com/30187/How-to-fix-issues-with-Double-NAT
Couple of options,
1. Configure the modem for transparent bridge or modem only mode. Then use the NG router in router mode. You'll need to contact the ISP for help and information in regards to the modem being bridged correctly.
2. If you can't bridge the modem, disable ALL wifi radios on the modem, configure the modems DMZ/ExposedHost or IP Pass-Through for the IP address the NG router gets from the modem. https://kb.netgear.com/25891/DMZ-on-NETGEAR-routers
https://kb.netgear.com/24086/How-do-I-set-up-a-default-DMZ-server-on-my-Nighthawk-router
3. Or disable all wifi radios on the modem and connect the NG router to the modem, LAN to LAN configure AP mode on the NG router.
https://kb.netgear.com/20927/How-do-I-change-my-NETGEAR-router-to-AP-mode
Try option #2 first...

[westy666]

ISP router is already in modem mode.

[westy666]

Also just to add a bit more info.

This config has been running fine for 2-3 years.

I haven't made any recent config changes to either the XR500 or the superhub.

The only thing that has possibly changed is the XR500 would have done a background firmware update. I'm probably going to turn the auto update off now so I have control over if\when that's done.

[FURRYe38]

BE sure it's in modem mode. The XR should get a ##.##.###.### IP address on it's internet port, not a 192. or 10.x address. 

[westy666]

Yep def in modem mode getting my ISP assigned IP address on the XR500 dashboard..

[FURRYe38]

What is all connected to the router when this happens? 

Try disconnecting everything and checking CPU usage to see if it drops in value? 

Does the top of the router feel extra warm or hot when this happens?

[westy666]

See above. Stays at 100% when everything is disconnected except my PC.

I'll have to wait to check the temp as it's not doing it right now.

[FURRYe38]

What is all connected to the router when this happens? Brand and model #s please of devices connected.

[westy666]

Do you want wired and wireless ?

Wired 

• Arlo Hub
• Hive Heating Hub
• My PC - Homebuilt - Built on MSI MAG X570 Tomahawk WIFI Motherboard
• Lenovo Thinkcentre M710q - Proxmox Server running HomeAssistant

If you need every wireless device that is going to take a while to compile.

As I said above when I disconnected everything the CPU% stayed high.

[FURRYe38]

If you can wireless when you have time. 

I'd go for a factory reset and setup from scratch. Also power OFF the ISP modem for 30 seconds then back ON.

I'd get a cooling fan under the router as well. 100% CPU usage would cause them to heat up and get hot. Having some cooling under the router will help keep CPUs cooler.

I keep one of these under any router I have online:

https://www.amazon.com/Thermaltake-Massive-Notebook-Cooling-CL-N014-PL20SW/dp/B00IGSATZY/ref=sr_1_3

or one of these: 

https://www.amazon.com/gp/product/B09FF5CRMD/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

[westy666]

Thanks for the suggestions.

I think part of my issue with this router is DumaOS seems so locked down you can't see what's going on under the hood. At least if could SSH into it I could see what processes are doing what to try and narrow things down a bit.

Think I'll try the factory reset tomorrow and see how that goes.

If not I might flash OpenWRT onto it and try that out.

[FURRYe38]

Something to try as well:

https://community.netgear.com/t5/Nighthawk-Pro-Gaming-Routers/NOTICE-NETDUMA-Beta-Firmware-for-the-N...

[westy666]

Thanks again.

So after about 4 days after a full factory reset and just running a basic config all seems to be ok.

I'll run it for a few more days before I start making any config changes.

Took a bit to get it to factory reset. Pushing the reset button for 30s wouldn't work but doing it through the interface did.

[FURRYe38 · Accepted solution]

Pressing for 10-15 seconds should be all that is needed on the reset button. 

Ya, I prefer using the ERASE button with in the UI. 

Glad you got it working. Please mark your thread as solved so others will know. Be sure to save off a back up configuration to file for safe keeping. Saves time if a reset is needed.
https://kb.netgear.com/000062080/How-do-I-back-up-the-configuration-settings-on-my-Orbi-WiFi-System