RAX45 "The IP address conflicts with the WAN IP subnet. Please enter a different IP address."

[GaryLC]

I am trying to add a Netgear Nighthawk RAX45 WiFi-6 to my network

My modem is a Modem/Router Netgear N450 (Cox)

There is also a Router Belkin 54G F5D72304

When I get this working, I want to replace my Netgear N450 with a Netgear CM1100.

 (my N450 has modem/wireless router/4 ethernet ports. The CM1100 is a modem only and I can't jump back and forth between modems with Cox until I get it working so want to get the RAX45 working with the N450 before I make the jump to the new modem.)

I currently have everything working on a local net of 192.168.56.xxx

There is a lot of detail here but most of the posts I see ask for this anyway. My local IPs are broken down in segments as follows:

Fixed IP
192.168.56.1	Netgear N450
192.168.56.2	reserved
192.168.56.3	reserved
192.168.56.4	reserved
192.168.56.5	reserved
192.168.56.6	reserved
192.168.56.7	reserved
192.168.56.8	reserved
192.168.56.9	reserved
192.168.56.10	reserved
192.168.56.56	Belkin
192.168.xxx.xxx	Netgear Nighthawk	RAX45 WiFi-6	192.168.56.200?
192.168.55.11	192.168.56.55	N450	DHCP
192.168.56.57	192.168.56.100	Belkin	DHCP
192.168.56.201	192.168.56.254	Netgear Nighthawk	DHCP
Printers
192.168.56.151	HP8720
192.168.56.152
192.168.56.153
192.168.56.154
192.168.56.155
192.168.56.156
192.168.56.157
192.168.56.158
192.168.56.159
192.168.56.160
NAS
192.168.56.13	WD My Cloud
192.168.56.161
192.168.56.162
192.168.56.163
192.168.56.164
192.168.56.165
192.168.56.166
192.168.56.167
192.168.56.168
192.168.56.169
192.168.56.170

Router Netgear Nighthawk RAX45 WiFi-6

Default: IP Pool Starting Address: 192.168.1.100       IP Pool Ending Address: 192.168.1.149

Desired: IP Pool Starting Address: 192.168.56.201       IP Pool Ending Address: 192.168.56.254

Anytime I try to set the Lan IP address to 192.168.56.200, I get the "The IP address conflicts with the WAN IP subnet. Please enter a different IP address." error.

I have seen multiple solutions, mostly dealing with DNS server settings. I haven't found any combination of Server Settings that work. Here is some of what I have tried.

Router Information:

MAC Address	08:36:C9:8E:5E:43   (MAC address on the Box)
IP Address	192.168.1.1

Internet Port

MAC Address	08:36:C9:8E:5E:44   (Router Mac Address)
IP Address	192.168.56.31
Domain Name Server	68.105.28.11

When I go to Advanced/Setup/LAN Setup and try to change the IP address to 192.168.56.200

The IP address conflicts with the WAN IP subnet. Please enter a different IP address.

If I change the IP address to 192.168.55.200, the router is happy and reboots to apply the setting.

Of course, I won’t be able to see anything else on my network.

Basic/Internet/Internet Setup

Internet Setup

Internet IP Address

Get Dynamically from ISP

Use Static IP Address

                                    IP Address      192.168.56.31

                                    Gateway IP Address   192.168.56.1 (the N450)

Domain Name Server (DNS) Address

                        Get Automatically from ISP

                        Use These DNS Servers

                                    Primary DNS  168.105.28.11

These settings have no affect whether I use automatic or static settings, so DNS server doesn't seem to fix it.

There is nothing else in my local LAN that is using the 192.168.56.200 - 192.168.56.254 address but I still get the error and no indication of what is causing it.

How can I get this to work with 192.168.56.?

Also, what is with the MAC address?

08:36:C9:8E:5E:43   (MAC address on the Box)

08:36:C9:8E:5E:44   (Router Mac Address) on the Internet port.

There must be 2 MAC addresses but what are they?

[antinode]

> My modem is a Modem/Router Netgear N450 (Cox)

   "N450" is a speed, not a model number.  Look for "Model" on the
product label.  Something like "CG3000D", perhaps?

> [...] want to get the RAX45 working with the N450 before I make the
> jump to the new modem.)

   Cascading multiple routers can cause multiple problems, especially if
you try to jam a square peg into a round hole.

   If you want to use the RAX45 as a router with your old modem+router,
then the reasonable thing to do would be to configure your old
modem+router as a modem-only.  You might then have a chance of
configuring the RAX45 with your desired LAN address scheme, without the
conflict with with your old modem+router which is using the same scheme
in a different place (hence, "The IP address conflicts with the WAN IP
subnet. Please enter a different IP address.").

   Visit http://netgear.com/support , put in your (actual) modem+router
model number (or something very like it), and look for Documentation.
Get the User Manual (at least).  Read.  Sadly, I saw nothing there like
what I expected to find, so it's not obvious that that thing has a
modem-only mode.  You might be able to get close if you configure
the thing with NAT disabled, and a LAN subnet other than your usual
"192.168.56.*".  (I'd try a settings reset, to restore its default
settings, then disable NAT, then connect the RAX45 to it, and see what
happens.

   I'd also save the configuration of your old modem+router before doing
any of this, so that you could more easily put it back as you had it.

   According to its User Manual, the CG3000Dv2 is so ill-suited for use
in this mode, that I'd go straight to the new modem and new router, and
run the grand experiment, rather than play with novel ways to simulate
a CM1100 using your old modem+router.  You might need to call Cox a few
more times, if you need to switch back and forth, but I'd take the
chance.

[GaryLC]

Netgear N450 is a CG3000Dv2

I will work on disabling the CG3000Dv2 router.

The problem I had with Cox is that when I first tried to enable the Netgear CM1100, it got part way through and then wouldn't complete the connection. Had to call Cox to trouble shoot. He didn't find anything obvious so we put every thing back to the CG3000Dv2. His suggestion was a service contract to track down the problem. I don't want to be completely down for several days while I trouble shoot connection problems.

[GaryLC]

Trying several settings to disable the CG3000Dv2 router part of the modem. Not having much success. Somehow, I managed to change the router address and now I can't connect at all. Will take time off work and go home and work on it. Think the only way I can get to the router now is to do a full reset. I am connected through a direct lan connection,not wireless.

I have no idea how the IP was changed. It may have happened when I disabled NAT. But I can't connect and have no way of determinging the current IP address. What ever it is, it is not 198.168.56.xxx. I have some internet connection but it is limited and some sites, like Netgear, won't respond at all. So at the moment, all if FUBAR. So will see what happens with a factory reset and then try to reconfigure to get back to where I was.

Have had good results with Netgear in the past which is why I went that way this time. But really frustrated with an error message that won't give you any indication of how to fix it. Looks like trying to upgrade with the Nighthawk RAX45 was a bad idea. Maybe better to start with a brand new network. Between computers, NAS, TVs etc, I probably have 50 devices potentially on the network. I don't wan't to have to build everything up from scratch.

[antinode]

> The problem I had with Cox is that when I first tried to enable the
> Netgear CM1100, it got part way through and then wouldn't complete the
> connection. [...]

   Nothing I can do about that, whatever it means.

> Trying several settings to disable the CG3000Dv2 router part of the
> modem. Not having much success. [...]

   Not much meat on that bone.

> [...] Think the only way I can get to the router now is to do a full
> reset. [...]

   That's typically a good way to restore normal operation after
misconfiguration.

> [...] I am connected through a direct lan connection,not wireless.

   You, personally, are "connected" to what?  Some computer or other is
connected to a LAN port on the RAX45, or the CG3000Dv2, or what,
exactly?  Wireless devices are on your LAN, too, but I'll take that as
meaning an Ethernet connection between something and something else.

> I have no idea how the IP [address] was changed. [...]

   Which one?  A router has two: LAN and WAN/Internet.

> [...] some sites, like Netgear, won't respond at all. [...]

   "Netgear" is a corporation, not a web site.  Actual URL?  And this is
with what as a modem, and what as a router, connected how?

> There is also a Router Belkin 54G F5D72304

   Doing what?  Connected to what, how?  (Hint: If a device has
different types of ports, then "connected to device" is not enough
detail.)

> [...] But really frustrated with an error message that won't give you
> any indication of how to fix it. [...]

   The "fix" is not to try to configure the WAN/Internet interface of
the router on the same IP subnet as its LAN interface.

> [...] Looks like trying to upgrade with the Nighthawk RAX45 was a bad
> idea. [...]

   I'd say that the bad idea was trying to use a CG3000Dv2 as a cable
modem-only when it apparently has no such mode of operation.

> [...] Maybe better to start with a brand new network. [...]

   If I wanted to make the RAX45 work, then I'd get a cable modem which
will work with your ISP.  If they can't puzzle out the CM1100, then I
might try a different maker and/or model.

> [...] Between computers, NAS, TVs etc, I probably have 50 devices
> potentially on the network. I don't wan't to have to build everything up
> from scratch.

   What's to "build up"?  With a working router, you should be able to
set the router's LAN IP address as you'd like it, and the wireless stuff
(SSID(s), passphrase(s)) to what you had before.  Then, with a working
modem, I'd expect all your client devices not to know the difference.

   I see that I overlooked this earlier:

> Also, what is with the MAC address?
> 08:36:C9:8E:5E:43   (MAC address on the Box)
> 08:36:C9:8E:5E:44   (Router Mac Address) on the Internet port.
> There must be 2 MAC addresses but what are they?

   Every network interface has a MAC address.  A router has two network
interfaces, LAN and WAN/Internet.  Which MAC address you want depends on
the interface of interest.  I'd expect both to appear on the ADVANCED >
ADVANCED Home page in the router's management web site.

[GaryLC]

I have a desktop computer directly connected to a wired LAN port.

Restoring the CG3000Dv2 router to original settings got me back to where I was before. And I am back on-line.

The Modem LAN IP was changed. I don't know to what. I couldn't connect to it at all, thus the reset. But the IP inconstincies reaked havoc throughout my network. I could get to Facebook, but the website for THIS forum (https://thf-membership.s3.amazonaws.com/2019_08_0309_GunControlEBook_V5.pdf?mkt_tok=ODI0LU1IVC0zMDQA...) was totally unavailable. Gmail was completely baffeled by the conflicting IP addresses and shut me down-also wouldn't let me enter passwords either. Using the CG3000Dv2 modem/router with an unknown IP address. I assume it was the LAN IP address since I couldn't connect to the modem through the LAN.

BTW, the CM1100 is specifically identified as being compatible with COX.

> What's to "build up"? With a working router, you should be able to
>set the router's LAN IP address as you'd like it, and the wireless stuff
>(SSID(s), passphrase(s)) to what you had before. Then, with a working
>modem, I'd expect all your client devices not to know the difference.

Exactly what I would expect, what I have done in the past with outher routers (even with multiple routers) and as long as I set the routers IP addresses not to conflict with other devices, it has worked. I will keep trying.

[GaryLC]

Try again.

“The IP address conflicts with the WAN IP subnet. Please enter a different IP address.”

Still getting this error when I try to create a local subnet.

LAN Setup

Device Name :   RAX45

LAN TCE/IP setup

IP Address          192.168.56.200

IP Subnet Mask:  255.255.255.0

RIP Direction: Both

RIP Version:       Disabled

Use Router as DHCP Server

Starting IP Address          192.168.56.201

Ending IP Address            192.168.56.254

“The IP address conflicts with the WAN IP subnet. Please enter a different IP address.”

So look at WAN IP:

WAN Setup

N             Disable Port Scan and DoS Protection

N             Default DMZ Server        192.168.1.0

N             Respond to Ping on Internet Port

Y              Disable IGMP Proxying

MTU Size(in bytes)          1500

NAT Filtering      Secured

(Absolutely nothing here about WAN IP Subnet)

Internet Setup

Does your internet connection require a login?   `No

Internet IP Address: Get Dynamically from ISP (but doesn’t matter if I try to use a static address)

Domain Name Server (DNS) Address       Get Automatically from ISP

Router MAC Address      Use Default Address

So the message provides no information about what is causing the error. Lot of people on the boards have this error and have difficulty fixing it. There are not IP conflicts using 192.168.56.200-192.168.56.254. There are other devices using 192.168.56.xxx but not this block. I have used multiple routers in this network in the past, including Netgear, and as long as the addressing doesn't conflict, there has not bee a problem. The error message is not useful in solving the problem.

It will let me use 192.168.1.xxx but I don't want to use that.