Receive "The IP address conflicts with the WAN IP subnet" when making LAN changes on Netgear device

The static IP setting for the LAN on the Prosafe is 192.168.1.1/255.255.255.0
The static IP setting for the WAN on the router is 192.168.1.101/255.255.255.0

Both networks are in the same subnet - 192.168.1.0/24.
WAN should be in the different subnet than LAN (since you have static IP, I guess that was assign by your ISP).
Set LAN subnet to anything but 192.168.1.0/24 (example 192.168.2.0/24, 192.168.0.0/24 etc).

Please note, the LAN port you are speaking of is on the Prosafe while the WAN port is on the Router and the two ports are connected.  My topology is:

ISP Modems (bridge mode) > Prosafe (rollover device between the two ISPs) >  Router > Switch

Thank you,

Don

Can you draw topology and mark IP addresses on interfaces to avoid confusion?

ISP Modems (bridge mode) > 
Public IPs ProSAFE 192.168.1.1/24 > 
192.168.1.101/24 Router 10.9.8.1/24 > 
10.9.8.x/24 Network Devices

I hope this helps.

Thanks for your help.

Don

I thought more like this, but change (mask) your public IP addresses on WAN.
:)
In my mind public IP (WAN) and LAN IP on Prosafe FVS336Gv3 should be different IP addresses, just like on R6300v2.

Your diagram works fine for me.  Just use the IP addresses you have marked.  Like your diagram, I have 4 different subnets: one for each ISP, one between the ProSAFE and the Router then one more for the LAN.

Have a great day,

Don

Than you should not have problems.
Some piece of slow internet performance could be caused by double natting. Once on every router, but I guess in most situations you should not notice that at all.

And also triple check LAN IP address on your R6300v2 router, since I don't see reason for message that you have mentioned if you have just turned off DHCP on second router and LAN is not in default DHCP range (192.168.1.0/24), so I guess router is still in default IP address range. Maybe router don't accept your 10.x.x.x/24 range and return default IP address for LAN (try 192.168.200.0/24 :) ), or something like that....

I'm not sure what you mean by 4 subnets as I only see, at most 2 or 3:

ISP Modems (bridge mode) > 
 Public IPs ProSAFE 192.168.1.1/24 > 
 192.168.1.101/24 Router 10.9.8.1/24 > 
 10.9.8.x/24 Network Devices

Here 192.168.1.1/24 is a Private IP Address with subnet 192.168.1.0/24
192.168.1.101/24 is another Private IP Address with the same subnet 192.168.1.0/24.

So, the point is that no device should have the same subnet on the WAN and LAN sides.
In order to avoid this, I try to assign a LAN subnet that's not likely to be used as a generic subnet.  Common ones are:
192.168.0.0/24
192.168.1.0/24
10.0.0.0/24
etc.

So, set the LANs that you can set to subnets like:
192.168.123.0/24
192.168.199.0/24
10.0.97.0/24
The chance that picking one like this will avoid the conflict now and into the future.

I do notice that some providers are doing the same thing for likely the same reason.  So, you may find your ISP device's LAN subnet being 192.168.99.0/24 .. something like that.  Still, if you avoid the common ones the likelihood of a matching conflict is low.  And, of course, you'll figure it out.

The big deal is if the ISP changes their device and introduces a new but common subnet on the LAN sie.  You want your own router's LAN to *not* match this to save the hassle to the user of having to reconfigure.

Resolved issue