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TroubleShooter9
Posts: 1
Registered: ‎07-18-2007

IP address and gateway is not at same subnet mask!

Everytime I try to change my modem settings, It tells me, "IP address and gateway is not at same subnet mask!"
 
Can anyone help please!?!?
helm
Posts: 3,650
Registered: ‎09-07-2006

Re: IP address and gateway is not at same subnet mask!

what device model number are you using ??
greiner86
Posts: 3
Registered: ‎07-24-2007

Re: IP address and gateway is not at same subnet mask!

I'm getting the same message. I'm on a WRT54G v. 6, with the most recent firmware upgrade. I'd appreciate the help!
Expert
Expert
Posts: 12,649
Registered: ‎07-16-2006

Re: IP address and gateway is not at same subnet mask!

What are you exactly changing on the router from what to what?
JorgeTU
Posts: 1
Registered: ‎09-06-2007

Re: IP address and gateway is not at same subnet mask!

I have the same problem. My ISP changed the modem and told me that I should use Static IP. The information they told me I should use is:
 
IP: 190.11.77.72
Mask: 255.255.255.224
Gateway: 190.11.64.73
DNS1: 200.58.72.15
DNS2: 200.58.64.15
 
Router: WRT54G v.6
 
As soon as I change the configuration and try to save it an error message porps up: "IP address and gateway is not at same subnet mask!"
 
But If I use the same parameters on my computer (connected directly to the ADSL modem) everything works OK.
Please help!!
Expert
Expert
Posts: 12,649
Registered: ‎07-16-2006

Re: IP address and gateway is not at same subnet mask!

Did they tell you to use PPPoE with a static IP address or just a plain simple static IP address?

Are you sure the subnet mask is correct?

In which adapter do you enter those numbers on the computer? Maybe it would help if you open a command prompt window and enter "ipconfig /all" and post the full output while you have a working internet connection.

Generally, the error message is correct. The gateway address is outside your LAN subnet. For correct routing it has to be inside the LAN and not outside (the gateway is the gateway from the inside to the outside and thus has two IP addresses one inside and one outside). If you choose a gateway address outside your LAN Windows seems to blow the gateway traffic simply to the ethernet hoping to find a destination...
gchagas
Posts: 1
Registered: ‎10-02-2011

Re: IP address and gateway is not at same subnet mask!

If the SubMask is 255.255.255.224, and the IP Address is 190.11.77.72, then the gateway should be 190.11.77.64

Expert
Expert
Posts: 12,649
Registered: ‎07-16-2006

Re: IP address and gateway is not at same subnet mask!


gchagas wrote:

If the SubMask is 255.255.255.224, and the IP Address is 190.11.77.72, then the gateway should be 190.11.77.64


Absolutely not. With netmask 255.255.255.224 and IP address 190.11.77.72, 190.11.77.64 would be the network address. No device in the subnet can use that IP address. It's reserved. Just like 190.11.77.95 is the broadcast address.

 

You cannot use 192.168.1.0 in a subnet 192.168.1.1/255.255.255.0 either.