I just finished configuring the new Nighthawk CAX80 cable modem/router Firmware Version: 1.1.0.41 and the DHCP reservations don't stick. I used the same IPs to MAC addresses relations and DHCP address range that used on my old Netgear WNDR4500 router that the CAX80 is replacing. The DHCP reservations on the WNDR4500 (N900) Firmware version 1.0.1.46_1.0.76 work as expected. The wired or wireless MAC addresses get the reserved IP address on the table. I have rebooted the CAX80 and re-entered the data in the DHCP reservation table a couple times, but it just does not work as expected. Is this a known issue? I found similar posts about other recent Netgear router models. There's very little info on this new modem/router. I'm posting this question here and also in the WiFi AX section of the community. This router is not yet listed in the Model "Recommended" line below the subject line to help the community.

What broswer are you using? How are you setting and applying IP address reservations. You have to add the reservations first, then when you on the LAN setup page, you have to select the Apply button. I would also reboot the devices your setting reservations for as well.

I have tried all the methods you just mentioned. Using Chrome, Firefox and Edge. I followed exactly the same process for the Netgear N900 which I own for 10 years. (The setup pages for DHCP reservation are almost exactly the same for both routers). If I remove and add a device from the reservation table on the N900 it works as expected. In the CAX80 it sticks for some devices, but fails to reserve for others without any consisttensy. My phone and laptop will get the reserved IP some times, but not all the time. Yes, I double checked the MAC + IP addresses.Everything works in the N900, but not in the CAX80 FURRYe38 wrote:What broswer are you using? How are you setting and applying IP address reservations. You have to add the reservations first, then when you on the LAN setup page, you have to select the Apply button. I would also reboot the devices your setting reservations for as well.

Do you have this other router connected to the CAX or you just switching back and forth? Might try a factory reset on the CAX and see if this changes anything.Try changing the default DHCP IP address pool size to 192.168.1.100 to .200. You might contact NG support and see if they can help you with this. vkdelta

Thanks.. I use one router or the other. They're not on at the same time. The wired reservations appear to stick, but not the wireless one. 2.4GHz appears to be more reliable with the reservations than the 5Ghz... I tried with and without Smart Connect enabled with the same results. Factory reset was one of the steps I took when I first noticed the issue.FURRYe38 wrote:Do you have this other router connected to the CAX or you just switching back and forth? Might try a factory reset on the CAX and see if this changes anything.Try changing the default DHCP IP address pool size to 192.168.1.100 to .200. You might contact NG support and see if they can help you with this. vkdelta

Nighthawk CAX80 Router-Modem - DHCP Reservations not working

4 Replies

FURRYe38
Guru - Experienced User
Aug 08, 2020
What broswer are you using?
How are you setting and applying IP address reservations. You have to add the reservations first, then when you on the LAN setup page, you have to select the Apply button.

I would also reboot the devices your setting reservations for as well.
- tamanaco
  Apprentice
  Aug 08, 2020
  I have tried all the methods you just mentioned. Using Chrome, Firefox and Edge. I followed exactly the same process for the Netgear N900 which I own for 10 years. (The setup pages for DHCP reservation are almost exactly the same for both routers). If I remove and add a device from the reservation table on the N900 it works as expected. In the CAX80 it sticks for some devices, but fails to reserve for others without any consisttensy. My phone and laptop will get the reserved IP some times, but not all the time. Yes, I double checked the MAC + IP addresses.Everything works in the N900, but not in the CAX80
  
  FURRYe38 wrote:
  What broswer are you using?
  How are you setting and applying IP address reservations. You have to add the reservations first, then when you on the LAN setup page, you have to select the Apply button.
  
  I would also reboot the devices your setting reservations for as well.
  - FURRYe38
    Guru - Experienced User
    Aug 08, 2020
    Do you have this other router connected to the CAX or you just switching back and forth?
    Might try a factory reset on the CAX and see if this changes anything.
    Try changing the default DHCP IP address pool size to 192.168.1.100 to .200.
    
    You might contact NG support and see if they can help you with this.
    vkdelta

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Nighthawk CAX80 Router-Modem - DHCP Reservations not working