Re: RAX120 DHCP Issues

dj2819 · ‎2020-05-01

I first want to say I been using Netgear products since the 54g days so I am familiar with them. However ever since I got FIOS back on 08 I haven’t used my Netgear routers as DHCP servers.

My last router was the R8500 which worked fine until I decided to remove the FIOS Gateway router and just use the R8500 as the DHCP server. That is when I started noticing a weird issue where randomly the router will kill all WiFi connections. The devices would re-connect usually after a few seconds but some didn’t. I couldn’t find a solution to that so I upgraded to the RAX120 hoping its price tag would make up for the vast number of devices I have.

So the RAX120 works great when it works without the weird all device disconnect of the R8500. The only problem was that randomly once or twice a day devices would drop their connection. Sometimes they would lose Wi-Fi, I saw once a self-assigned ip get set, and other times it would be connected with a valid IP but no internet access.

After a few weeks of digging, firmware upgrades/downgrades I think I figured out the issue. I have 20 or so devices that are always connected (3 wired, 4ish on 2.4ghz and rest on 5ghz (AC,AX devices). Looking at the logs it looks like for some reason every 12 hours a DHCP renewal happens. Weird that it is 12 hours even though 24 hours is what the router has set.

My theory became that every time the router is booted up or when the DHCP renewal happens, the RAX120 is hit with 20+ devices all renewing at the same time. I figure due to some reason the router might be trying to assign the same IP to 2 or more devices. This could be because the devices are MU-MIMO enabled and they are connecting too fast. Or it could be that this router has a quad-core and there is some race-condition when that many DHCP requests are coming in at the same time.

Whatever the case the only solution that seems to work right now is to reserve a bunch of IPs high up in the IP range for all of those devices that remain connected 24/7. When their DHCP leases due expired the server doesn’t struggle to provide a new lease and there is enough breathing room in the lower IP range for existing/new devices.

I really hope the firmware team takes a look at this post. They need to stress test use-cases such as this especially with devices getting faster and multiple connections possible at once (MU_MIMO and OFDMA).

dj2819 · ‎2020-05-21

I guess the solution would be avoid the RAX120 and possibly the RAX line until they fix their firmware. Networks with many always on devices will stuggle with this router. Netgear really needs to listen to the reviews and user feedback because something is clearly wrong with this device.

Switched to the Linksys Velop MX5 and everything works perfectly right out of the box (thank god because custom settings on it is non-existant).

So long Netgear, it was a nice decade of relible devices.

View solution in original post

dj2819 · ‎2020-05-04

The DHCP issues returned eventually even with IP reservation so I gave up on Netgear as a DHCP server. To be frank I don't even remember the last time I used the DHCP server of Netgear as the Fios router always handled that for me since 2009.

Well I broke out my old Fios router, set up the RAX120 in AP mode and no issues so far. Everything has been rock solid for about 2+ days of uptime.

@netgear You really need to double check your DHCP server firmware code on your routers. I believe there is something seriously wrong in your new devices when multiple devices are involved. It sucks that these expensive routers can't handle the simple task of DHCP...

dj2819 · ‎2020-05-11

Update: Even with the Fios router I faced some issues but not as bad as the original disconnects. I replaced the Fios router with an EdgeRouter ER-X. So currently the EdgeRouter acts as the DHCP server and the RAX120 is just in AP mode.

What I learned is given 1-2 days from the original DHCP lease, the iPhone 11s or one of the 7 HomePods I have randomly lose connection.

The iPhones show as connected in the OS but the router's GUI nor pinging their IPs does not work. Flipping the iPhone's Wi-Fi on and off fixes the issue until another day or 2 later.

The HomePods face a similar issue where they lose connection (no OS GUI to check if its actually showing as connected) and they are not pingable.

Window's PC shows as connected with no internet

I am getting fed up with this router. I had Amazon send me a replacement. If that doesn't work I will try to turn of AX features. If that doesn't work then goodbye @netgear (after a whole decade of their products)

Robdarftw · ‎2020-05-20

@dj2819 Hey hope you get this message.

I am having the exact same issue and about the same setup. I have about 3 or 4 wired connections (2 of which are connected to a Nighthawk switch) and the rest are on Wi-Fi with AX mode enabled.

What's weird is, only my wired connections seem to be affected are straight up losing DHCP and not getting a new IP from the DHCP server - in this case the Netgear Nighthawk RAX120 - even with a release/renew.

I have the updated firmware that was released a few weeks ago, and I have recently added a Google Home to my network, but thats the only thing I can think of that has changed.

When I get home I am going to try to reset the RAX120 and set it up from scratch, as those DHCP reservations aren't doing a darn thing.

I'll let you know if I find anything else.

-Rob

dj2819 · ‎2020-05-20

Hey @Robdarftw, sorry I haven't updated this thread in a long time.

I been posting updates on other threads. Basically I don't think it is a DHCP issue for me anymore. Using a EdgeRouter X as the DHCP server I experienced the same issues. I think DHCP has something to do with maybe collisions or some conflict on the network because when I decreased the DHCP lease time to 1 hour (from 24 hours) the issues happened more frequently (within 4-5 hours).

Then I realized this might just be an issue with the 5Ghz band.

I tried getting in touch with Netgear support but oh what a **bleep** show that was. I had ONE (the first) phone tech who was profressional, accepted that I knew what I was doing, listened to the month of troubleshooting I did (which was the same questions/steps he was going to present to me) and said the ticket needs to get escalated. However that case got closed (for whatever reason) and the new ticket I opened got no responses after I explained the same situation. Calling again resulted in them hanging up on me or dropped calls when they transfered me to the RAX dept.

The second case rep suggested I isolate all my devices to one band. So I moved everything to the 2.4ghz band and left one device on the 5Ghz band. Weird thing was I saw the same issue occur on the 5Ghz band and once on the 2.4ghz band (but much less frequently).

I then tried something I wish I tried earlier. When I upgraded from my old router to the new one, I set the new one with the same SSID and PW. I tried another factory reset and kept the default wifi settings. This didn't help either.

So where I am now is I have just setup the Linksys Velop MX-5 as an AP. If this works without issue then goodbye Netgear. I really tried for over a month to keep this product because I have brand loyalty. But Netgear doesn't give two sh*ts and my experience with their past 2 generation of products was really bad. I really hope this new router works so then I can narrow the issue to the router and not the devices....

Robdarftw · ‎2020-05-20

Ya netgear consumer support is horrible, but so is Linksys. The Velops are nice, I hope it fixes your issue.
At this point after all your troubleshooting, I’m thinking it’s gotta be a device on my network somehow not wanting to release it’s IP or something and causing a conflict. I’m going to say the Google Home or that netgear switch.
I’m going to try with them removed and see how it goes for a couple days.

dj2819 · ‎2020-05-20

@Robdarftw You could try to enable Telnet on the router and clearing your DHCP lease table. And then connect one device at a time. That is the only way I think to get a new IP assigned to your devices, unless you reserve the IP or manually assign the IP on the client. I found that it needs a reboot for that to take effect.

dj2819 · ‎2020-05-21

I guess the solution would be avoid the RAX120 and possibly the RAX line until they fix their firmware. Networks with many always on devices will stuggle with this router. Netgear really needs to listen to the reviews and user feedback because something is clearly wrong with this device.

Switched to the Linksys Velop MX5 and everything works perfectly right out of the box (thank god because custom settings on it is non-existant).

So long Netgear, it was a nice decade of relible devices.