Hey All,

So, I bought this REALLY nice C7000 Nighthawk cable modem router and I want to use it instead of the old cheap Comcast cable modem here.

I have "upgraded" dozens and dozens of the cheap Comcast cable modem routers over the years with no problem.

I have already configured the WAN side and it sees the web just fine.

I have also configured the wireless just the way I want it.

Final step was to change the LAN IP in this cable modem/router to 192.168.100.254 (I can change the last octet to anyone that is not currently being used on this network). But I need the first three octets to be 192.168.100.

But EVERY TIME I change the LAN IP from the default of 192.168.0.1 to the IP of 192.168.100. ____ I get an error message of:

"FAILURE Invalid data. LAN IP address overlapped"

Now, before someone suggests it is because of DHCP routing I have both tried disabling DHCP AND leaving it on but set to a different range FAR away from the address that I use for the IP Address. Example: If I set the LAN IP to 192.168.100.254...... I set the DHCP range to 192.168.100. 70 TO 192.168.100.75 WITH NO CHANGE.... same error message. And I have tried several different combinations..... no help.

I AM able to change the IP address to another IP like 192.168.1.1 etc. just fine. but NOT to the IP address that I absolutely positively need.

There does not appear to be anything else in this cable modem/router that is using the IP of 192.168.100. ____ so, there is NO overlap. Not even the guest wireless as some other posts have suggested.

I have tried everything I can think of with no success. But perhaps I have missed something. So, if anyone has a fix I would greatly appreciate it.

Thanks in advance (smile)

Forum Discussion

C7000 Can not change LAN IP to 192.168.100.___