Difficulty using a CAX30 and MR60 router together

[JolietJake]

I have a CAX30 modem/router connected to Xfinity in the basement where the cable comes in and the home ethernet is run.  It has 2 hardwired connections to devices as well as a hardwired connection to a MR60 on the first floor.  I am able to get it set up and running where the CAX30 uses the 192.168 domain and the MR60 uses the 10.0 domain.

However, due to power issues in the area, we will get flashes of a power outages where everything reboots.  When it reboots, the MR60 does not connect properly to the CAX30 and reverts to the 192.168 domain until I hardwire a connection from a laptop to the MR60.  It will then revert to the 10.0 domain.

The other day the MR60 switched itself to the 172.16 domain causing havoc with the MoCa network that I have set up.  I could not get the MR60 to revert to the 10.0 domain resulting in a hard reset of the MR60.  

What is the best way to permanently fix the MR60 to the 10.0 domain?  Will that fix the issue of reconnecting to the CAX30?

I have tried battery backups on both devices but that does not fix the issue of how or why the MR60 started using the 172.16 domain.  

Thanks for any insight that can be provided.  

[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. 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. Change the CAX30 to Mode only mode. Under Advanced Tab/Advanced/Router mode to NO. 
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

[JolietJake]

Thanks for the info and the reply. 

If I do option 1, will the 4 RJ45 ports on the modem remain active?  I prefer to not find out with trial and error.

[plemans]

I would use option 3. 

I'd leave the cax30 in router mode with wifi enabled. 

Then I'd put the MR60 in access point mode.

Just make sure to have the 2 wifi networks on different channels to prevent interference. 

then you can use the devices near the cax30 for faster speed (higher capability) and the MR60 for those devices that roam/travel around. 

[FURRYe38]

IF you do option 1 on the modem, the ports are not active for use for any LAN side devices. However they can become a port used for ISPs that support having more than one WAN IP address from the ISP. Most home ISPs may not support this. Mine does and when I have my CAX80 in modem mode, I can connect additional routers to the back of the CAX80 and each of them get a different WAN IP address. Some ISPs may support this on a Business class service account. Mostly home users only need 1 WAN IP address so if you choose option #1, thats all you'll need and just know that the other ports would not be used at all in this mode. I recommend either putting the CAX30 in modem mode and use the MK system as your host router if you want to to use it's router features. Other wise to keep things simple, turn off the CAX30s wifi radios and configure AP mode as suggested in #3. 

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@JolietJake wrote:

Thanks for the info and the reply. 

If I do option 1, will the 4 RJ45 ports on the modem remain active?  I prefer to not find out with trial and error.

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