Nighthawn CAX30 Cable Modem will not DHCP IPv4 addresses after Wifi Customization

[TonyGinSLC]

I am using a Nighthawk CAX30 cable modem/router with Infinity.

When it first bring up the device, all works well.  However, once I customize the Wifi settings (SSID, password, etc.) the router stops DHCPing IPv4 addresses. It hands out IPv6 addresses fine, but no IPv4.

I am running the latest available firmware (V1.4.10.4).

I had gotten things to work correctly for about one week by enabling "Smart Connect".  I don't know why that resolved things temporarily, but it did.

However, when I woke up this morning devices were once again only receiving IPv6 addresses.

I did a factory reset and the same behavior was present, i.e., leaving all default settings all works well. After customization of WiFi settings, no more IPv4 addresses.

Initially Netgear thought the device was defective and sent me a replacement. Same issue on the replacement.

Now Netgear support seems to have no idea why this is happening and does not have a resolution.

I would revert back to my Xfinity Xfi, but since things were working fine for a week, I've return it.

Has anyone else seen this behavior?  I have seen a couple of posts from folks having this issue, but no references to a resolution.

Thanks all.

--Tony

[michaelkenward]

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@TonyGinSLC wrote:

I am using a Nighthawk CAX30 cable modem/router with Infinity.

You have posted your message in the section of this community given over to Nighthawk WiFi Routers. (This is easily done, given Netgear's complicated community structure.)

Many questions apply to different types of device, so you might get responses here, but the "CAX" devices aren't bog standard routers, so you might get more help, and find earlier questions and answers specific to your hardware, in the appropriate section for your device. That's probably here:

Cable Modems & Routers

It is where fellow users may be able to answer this question:

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@TonyGinSLC wrote:

Has anyone else seen this behavior?  I have seen a couple of posts from folks having this issue, but no references to a resolution.

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I will ask the Netgear moderator to move your message.

In the meantime you could visit the support pages:

Support | NETGEAR

Feed in your model number and check the documentation for your hardware.

You may have done this already. I can't tell from your message.

I mention it because Netgear gave up on supplying paper manuals years ago and people sometimes miss the downloads.

[TonyGinSLC]

This is a CAX30s.

Actually this is (kind of) resolved. The fix is that the WiFi passwords must only contain numbers and letter. They have escalated this issue to the engineering team as this is more of a temporary fix than a permanent solution.

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@michaelkenward wrote:

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@TonyGinSLC wrote:

I am using a Nighthawk CAX30 cable modem/router with Infinity.

You have posted your message in the section of this community given over to Nighthawk WiFi Routers. (This is easily done, given Netgear's complicated community structure.)

Many questions apply to different types of device, so you might get responses here, but the "CAX" devices aren't bog standard routers, so you might get more help, and find earlier questions and answers specific to your hardware, in the appropriate section for your device. That's probably here:

Cable Modems & Routers

It is where fellow users may be able to answer this question:

---

@TonyGinSLC wrote:

Has anyone else seen this behavior?  I have seen a couple of posts from folks having this issue, but no references to a resolution.

---

I will ask the Netgear moderator to move your message.

In the meantime you could visit the support pages:

Support | NETGEAR

Feed in your model number and check the documentation for your hardware.

You may have done this already. I can't tell from your message.

I mention it because Netgear gave up on supplying paper manuals years ago and people sometimes miss the downloads.

---

[iRyan]

I've been experiencing this exact same issue since I first purchased it back in May. Netgear also sent me a replacement after troubleshooting with both my ISP Comcast and Netgear support for 2+ hours over the phone. All other settings I change take effect without any issues, but as soon as I go into my advanced LAN setup and start reserving IP address reservations my CAX30 will not let any of my devices connect to it (wired and wireless). I have even gone so far as to get on every single device, remove the network from device memory, manually reset every network setting, and do a full reboot of the devices. Still won't let a single device connect to it. SOMETIMES a device will connect to the wireless SSID, but the network status will say it is connected without internet access. Once I restart the CAX30 I will be able to wirelessly connect my laptop to the network just long enough to remove the IP address reservations from DHCP and everything is back to normal once I apply the changes. 

Here is all of my relevant information:

- Hardware version 1.01

- Firmware version 1.4.10.8

- Cable firmware version 1.04.10

- CM certificate installed

- Windows 10 Home Version 21H1

- OS Build 19043.1081

I saw somewhere that this bug can be avoided by using only letters and numbers in your SSID password, but my PW has only always been letters/numbers and the issue still persists. I would GREATLY appreciate any help and feedback that anyone may have. Thank you!